- Who wrote the Vedas and why?
- How did the Vedas exist since their inception?
- Where can we read the Vedas?
The Vedas are Śruti, which means "that which is heard" (what Christians would call "revelation"). Hindus believe that from time immemorial, sages known as Dhrishtas (literally "seers") have, during a state of Tapasya (deep meditation), heard sacred verses directly from the gods. In the Dwapara Yuga (the age before the one we're currently in), these verses were compiled by a sage named Krishna Dwaipayana Veda Vyasa (or Vyasa for short) into a set of four books we call the Vedas. (Technically Vyasa only compiled the first three books - Rig, Yajur, and Sama - while the Atharvana Veda is attributed to the sages Angiras and Atharvan.) As the words of the Vedas are believed to be divine in origin, they are held to be the foremost authority of the Hindu religion. As Rama says in the Ayodhya Kanda of the Ramayana, the Vedas "have the foundation in Truth [and] one should thoroughly surrender to truth."
I should add that each of the four Vedas is divided into four portions: Samhitas, the core part of the Vedas which consist of hymns to various gods; Brahmanas, which provide instructions on the proper conducting of important rituals; Aranyakas, which provide a guide to rituals meant for forest-dwellers and hermits; and Upanishads, which consist of conversations between teachers and students which clarify the philosophical message of the Vedas. In any case, when someone says "I read the Rig Veda" without qualification, they usually mean the Rig Veda Samhita, because the Samhitas are the core part of the Vedas which came directly from the gods.
(Note: the above is excerpted from my answer here.)
As for where you can read the Vedas, sacred-texts.com is a good site. Here's the Rig Veda Samhita, the Krishna Version of the Yajur Veda Samhita, the Shukla version of the Yajur Veda Samhita, the Sama Veda Samhita, the Atharvana Veda Samhita, the Shatapatha Brahmana of the Yajur Veda, some major Upanishads from various Vedas, and some minor Upanishads.
The traditional answer to the question as to how the Vedas came into existence is that the Vedas are eternal! The traditional answer to the question as to who wrote the Vedas is that there are no writers! Vedas are anadi or beginning-less. Some Hindus (those who follow Purva Mimamsa Darshana) and probably others still hold to these views literally. Is there any way to understand the claims of Vedas being beginningless and eternal in a non-literal sense? I am posting below Swami Vivekananda's views on the Vedas:
There was a time when the Vedas themselves were considered eternal in the sense in which the divine truths contained therein were changeless and permanent and were only revealed to man. At a subsequent time, it appears that the utterances of the Vedic hymns with the knowledge of its meaning was important; and it was held that the hymns themselves must have had a divine origin. At a still later period, the meaning of the hymns showed that many of them could not be of divine origin, because they inculcated upon mankind performance of various unholy acts, such as torturing animals; and we can find many ridiculous stories in the Vedas. The correct meaning of the statement "The Vedas are beginning less and eternal" is that the law or truth revealed by them to man is permanent and changeless. Logic, geometry, chemistry, etc., reveal also a law or truth which is permanent and changeless and in that sense they are also beginning less and eternal. But no truth or law is absent from the Vedas, and I ask any one of you to point out to me any truth which is not treated of in them. (Vivekananda Complete Works (CW), Vol.5: With the Swami Vivekananda at Madura, pp.205-206)
The Hindus have received their religion through revelation, the Vedas. They hold that the Vedas are without beginning and without end. It may sound ludicrous to this audience [in the West] how a book can be without beginning or end. But by the Vedas no books are meant. They mean the accumulated treasury of spiritual laws discovered by different persons in different times. Just as the law of gravitation existed before its discovery and would exist if all humanity forgot it, so is it with the laws that govern the spiritual world. The moral, ethical, and spiritual relations between soul and soul and between individual spirits and the Father of all spirits were there before their discovery, and would remain even if we forget them. (CW, Vol.1: Paper on Hinduism, pp.6-7.)
The Vedas are anadi, eternal. The meaning of the statement is not, as is erroneously supposed by some, that the words of the Vedas are anadi, but that the spiritual laws inculcated by the Vedas are such. These laws, which are immutable and eternal, have been discovered at various times by great men or rishis, though some of them have been forgotten now, while others are preserved. (CW, Vol.6: Notes Taken Down in Madras, 1892-93, p.103)
Even before mankind, the Vedas existed. Krishna says:
'aham eva vedya': I know Vedas and mankind knows me from Vedas.
Vedas are 'apauruSheya'.
Bhagavata says Vedas were there in all yugas. Vedas are to be found by meditating and propagating what is found. It's not prayers. Like how Vishwamitra found the Gayatri and it became known as the Vishwamitra Gayatri (Mantra) and himself became a Rishi for that.
vEdaasthe nityavinnathvaachruthayaashaakhilai: shrutE: |
Amnaaya anyathaapaataadheesha bhudhisthita sada ||- Iti varahe
This smrithi says that Vedas existed all the time and were not written by any single person or by a collection of people. They have always existed in the mind of Lord all the time! So Vedas are as ancient as God. They were not created by God and they just existed with him. That's why Krishna says Vedas are by which you can know me.
Who wrote the Vedas and why?
Vedas do not have a mundane mortal creater. They manifested from the Supreme Lord and they are eternal like the Supreme Lord. In Srimad Bhagavatam 6.1 yamadutas tell the Visnudutas
vedo narayanah saksat svayambhur iti susruma - 'The Vedas are directly the Supreme Personality of Godhead, Narayana and are self-born. This we have heard from Yamarāja'
Also in the first verse of Srimadbhagavatam Vyasadeva says
'om namo bhagavate vasudevaya ... ene brahma hrda ya adi-kavaye' He offers respects to
vāsudeva, the son of Devaki, and says He revealed
brahma (another name of Vedas) to
ādi-kavi (Lord Brahma) with in his heart.
More clearly we find in Srimadbhagavatam 11.14.3 where
Lord Krishna tells
sri-bhagavan uvaca kalena nasta pralaye vaniyam veda-samjñita mayadau brahmane prokta dharmo yasyam mad-atmakah
The Supreme Personality of Godhead said: By the influence of time, the transcendental sound of Vedic knowledge was lost at the time of annihilation. Therefore, when the subsequent creation took place, I spoke the Vedic knowledge to Brahmā because I Myself am the religious principles enunciated in the Vedas.
Now we know that they are eternal and came from the Supreme Lord, the purpose of the Vedas is like the manual of a product. They are the manuals to give us knowledge of this material world and also the means to attain the goal of human life.
How did the Vedas exist since their inception?
Just like I mentioned above they were transmitted to Brahma and came down in disciplic succession. From Brahma to Narada and other saints. Narada gave them to Vyasa. They existed in the sound form and from the time of Vyasa some form of transcription started. Unlike the modern idea that civilization is advancing the Vedic idea is that people are actually degrading as kali yuga progresses. Their memory is not as strong now. In the previous ages, due to practicing strict life of celibacy and austerities, the students of Vedas had sharp memories.
Where can we find the Vedas to read?
This is not a trivial thing. Vedas cannot be understood with out the help of a teacher. This is given in the Vedas itself. While you can find some versions floating on the internet the authenticity of some of the content is questionable. Five hundred years ago the stalwart genius Jiva Gosvami wrote a detailed, logical, technical work called tattva sandarbha in which he addresses the issue of what constitutes Vedas and how should we approach them in this modern day. He points out the certain portions of the Vedas are actually not available now and there exists many confusing interpretations as well.
I found from a sanskrit scholar (Gopiparanadhana dasa) that at present only 11 samhita, 18 Brahmanas, 7 Aranyakas and 220 Upanishads are available. This constitutes only 6% of what is stated in Kurma Purana.
So Jiva Gosvami says that the puranas and itihasas constitute much better, authentic and reliable knowledge. He cites Mahabharata adi-parva and the Manu Samhita whic states 'One should complete one's understanding of the Vedas with the help of puranas and itihasas'. Also it is said the Puranas are called by that name because they 'complete'. You cannot complete something which is not of the same nature so Puranas are actually part of Vedas. Jiva Gosvami addresses the concern some may have in considering puranas as Vedas.
He cites from the passage of Madhyandina Sruti, Brhad-aranyaka Upanishad 2.4.10 which states 'Thus indeed the breath of the Supreme Being constitues the Rg Veda, Yajur Veda, Sama Veda, Atharvangirasa Veda, Itihasa and Purana'. Bhagavatam says originally the Veda was one and Vyasa divided into four. He also cites several other sources like Skanda Purana. Interested can look up for 'Tattva Sandarbha' translation by Gopi Paranadhana Dasa.
Srimad Bhagavatam also calls Puranas as fifth Veda:
itihasa-puranani pañcamam vedam isvarah sarvebhya eva vaktrebhyah sasrje sarva-darsanah
Then he created the fifth Veda — the Puranas and the histories — from all his mouths, since he could see all the past, present and future.
So while you can find some texts of Rg, Yajur, Sama and Atharva by googling around, the contents will not complete and the interpretations/translations may not be fully accurate. You would be better off with some well known upanishads like Isopanishad and speific Vedanta Sutra citations in commentaries to texts like Bhagavata Purana. Best is to take the summary of all Vedas that is given by Vyasa in the top most Bhagavata Purana. You can find one commentary here.
All the Vedic texts are eternal and appeared from the Supreme Lord:
Atharva Veda 11.7.24:
rcah samani chandamsi puranam yajusa saha ucchistaj-jajnire sarve divi deva divi-sritah
"The Rg, Sama, Yajur and Atharva became manifest from the Lord, along with the Puranas and all the Devas residing in the heavens."
Atharva Veda 15.6.10–12:
sa brhatim disam anu vyacalat tam itihasas ca puranam ca gathas ca itihasasya ca sa vai puranasya ca gathanam ca narasamsinam ca priyam dhama bhavati ya evam veda
"He approached the brhati meter, and thus the Itihasas, Puranas, Gathas and Narasamsis became favorable to him. One who knows this verily becomes the beloved abode of the Itihasas, Puranas, Gathas and Narasamsis."
Madhyandina-sruti, Brhad-aranyaka Upanisad 2.4.10
asya mahato bhutasya nihsvasitam etad yad rg-vedo yajur-vedah sama vedo’tharvangirasa itihasah puranam ityadina
“O Maitreya, the Rg, Yajur, Sama and Atharva Vedas as well as the Itihasas and the Puranas all manifest from the breathing of the Lord.”
Gopatha Brahmana, purva 2.10
evam ime sarva veda nirmitah sa-kalpah sa-rahasyah sa-brahmanah sopanisatkah setihasah sanvakhyatah sa-puranan
“In this way, all the Vedas were manifested along with the Kalpas, Rahasyas, Brahmanas, Upanishads, Itihasas, Anvakhyatas and the Puranas.”
Kauthumiya Chandogya Upanisad 7.1.4
nama va rg-vedo yajur-vedah sama-veda atharvanas caturtha itihasa-puranah pancamo vedanam vedah
“Indeed, Rg, Yajur, Sama and Atharva are the names of the fourVedas. The Itihasas and Puranas are the fifth Veda.”
All this texts appeared from the supreme Person and transferred from generation to generation through various disciplic chains as described in Srimad Bhagavatam canto 12, chapter 6 and 7: Vedabase.com/en/sb/12
Surprisingly, the other answers all only give various versions of traditional beliefs on the origin of the Vedas proper but not the historical truth.
See the surprisingly well-curated Wiki article RigVeda for the actual historical truths about the origin of the Rig Veda. Its dating information etc. are sourced from scientific scholarship (as of this posting).
The Vedas were not written but were composed orally by human poets arising amidst native speakers of Vedic Sanskrit, with the earliest Veda, the Rig Veda, composed over hundreds of years 1500-1200 B.C in the North West of the Indian subcontinent. Other vedas are for the most part younger than the Rig Veda with the Atharva Veda being the youngest of them all.
The authorship of most of the mandalas of the Rig Veda is, by tradition itself, attributed via the Anukramaṇī to poets from individual families such as the Kaṇvas, Viśvāmitras, Atris et al.
The Vedas were trasnmitted strictly orally with an ingenious system of recitation put in place when the Aryans settled in Kurukṣetra to ensure that no errors crept in. That system has preserved certain very minute tones that escaped even the notice of traditional grammarians. The Rig Veda was written down only about a millenium ago.