Nyasa was already explained here.
The following explanation on Mahanyasa and Laghunyasa can be found here.
FIVE FACES OF SHIVA:-
Because of his five faces Shiva has the name pañcavaktraḥ।
pañcasaṅkhyākāni vaktrāṇi mukhāni nānārūpāṇi yasya sa tathā ।
These faces have the following names. īśāna, ...
It is not Ok to sing mantras.
Here is an article about the Devi Mahatyam (Chandi Patha) on Hindupedia.com that discusses about the various rules and regulations of reciting it.
The full reading can also be done over seven days viz one chapter on
the first day, next two chapters on the second day, next one chapter
on the third day, next four chapters ...
The seers of Rig Veda expressed their SPIRITUAL EXPERIENCES through mantras. Those mantras were composed in a cryptic language.
Apart from eulogising the various aspects of the Almighty as Vishnu, Indra, Agni, etc, the union of Male and Female energies of the same Almighty was narrated as Bliss of SOMA, in a subtle manner.
The eulogisation of the Almighty ...
For this purpose we don't have Mantras but we do have Stotras.
From this page you can learn for example the Shiva Aparadha Kshamapana Stotram, which is asking for forgiveness from Lord Shiva for the faults the devotee might have committed.
Aadau karmaprasangaat, kalayati kalushham, maatrikukshau-sthitam
maam, Vin-muutraa-medhya-madhye, kathayati ...
In case of RV X.137 which has exactly 7 verses, the Anukramaṇī lists the seer for each mantra of the sūkta separately. So, the first mantra was revealed to Bharadvāja, the second to Kaśyapa, and so on.
| Hymn (Sūkta) | Deity (Devatā) | Seer (Ṛṣi)...
It is always advisable to take a mantra, containing bIjAksharAs like aim, klim, etc, from an accomplished Guru. An accomplished Guru will be knowing which mantra will suit to one aspirant. There are 2 phases in getting siddhi of a mantra. (1) Priliminary stage, where an accomplished Guru will study the nature of the aspirant and initiates one into ...