Where can I find the Gayatri mantra commonly used?

Question

Where can I find the Gayatri mantras for deities commonly worshipped like Lord Shiva, Vishnu, Brahma etc?

I found some video from YouTube but not sure if its safe to chant.

Answer 1

One can find Gayatri Mantras for many Deities in the minor Upanishad called Mahanarayana.

Or else one find some of them from Linga Purana too:

The various Swarupas of Gayatri as created by Maha Deva and the related Mantras are:

Tatpurushaaya vidmahey Vaagshuddhaaya Dhimahi tannah Shivah Prachodayaat

Ganaambikaayai vidmahey Karma saadhyaih cha dhimahi, Tanno Gauri Prachodayaat/

Tatpurushaaya vidmahey Maha Devaaya Dhimahi, Tanno Rudrah prachodayaat/

Tatpurushaaya vidmahey Vakratundaaya Dhimahi, Tanno Dantih prachodayaat/ (this is for Lord Ganesha)

Maha Senaaya vidmahey Vaagvishuddhaaya dhimahi,Tannah Skandah prachodayaat/

Tikshna shringaaya vidmahey Veda paadaaya dhimahi, Tanno Vrishah prachodayaat/

Harivaktraaya vidmahey Rudravaktraaya dhimahi, Tanno Nandee prachodayaat/

Naraayanaaya vidmahey Vaasudevaaya dhimahi,Tanno Vishnuh prachodayaat/

Mahaambikaayai vidmahey karma siddhaaih dhimahi, Tanno Lakshmi prachodayaat/

Samruddhaayai vidmahey Vishnunaikena dhimahi, Tanno Dharaa prachodayaat/

Vainateyaaya vidmahey Suvarna pakshaaya dhimahi, Tanno Garudah prachodayaat/

Padmodbhavaaya vidmahey Veda Vaktraaya dhimahi, Tannah Srashta prachodayaat/

Shivaasya jaayai vidmahey Deva rupaayai dhimahi, Tanno Vaachaa prachodayaat/

Devaraajaaya vidmahey vajrahastaaya dhimahi, Tannah Shakrahy prachodayaat/ (this is for Indra)

Rudra netraaya vidmahey Shaktihastaaya dhimahi, Tanno Vahnih prachodayaat/

Vaivaswataaya vidmahey Dandahastaaya dhimahi, Tanno Yamah prachodayaat/

Nishaacharaaya vidmahey Khadga hastaaya dhimahi, Tanno Nirrutih prachodayaat/

Shuddhahastaaya vidmahey Paasha hastaaya dhimahi, Tanno Varunah prachodayaat/

Sarva Praanaaya vidmaheyYashti hastaaya dhimahi,Tanno Vaayuh prachodayaat/

Yaksheswaraaya vidmahey Gadaa hastaaya dhimahi, Tanno Yakshah prachodayaat/

Sarveshwaraaya vidmahey Shula hastaaya dhimahi,Tanno Rudrah prachodayaat/

Katyaayanaaya vidmahey Kanya kumaaryai dhimahi,Tanno Durgaa prachodayaat/

The Gayatri Mantras for various Deities are also found on Hindupedia.com :

But none of the sites contain the respective Mantra for Lord Bhairava.

You can find his Mantras from this page.

Om Kalakalaya Vidmahe Kalathithaya Dhimahi Thanno Kala Bhairva Prachodayath.

OR

Om Soola Hastaya Vidmahe Shvana Varaya dhimahi Thanno Bhairava Prachodayath

As regards, whether it is safe to chant them by looking them up from books or random sites-- then it is not. Unless you know how to pronounce correctly, you are wearing the sacred thread or you're having a Guru Diksha.

EDIT:

Gayatri Mantras for Lord Krishna:

Om Damodaraya Vidmahe Rukmini Vallabhaya Dhimahi Tanno Krishna Prachodayath.

Or

Om Devaki Nandanaya Vidmahe Vasudevaya Dhimahi Tanno Krishna Prachodayath.

For Gopala it is:

Om Gopalaya Vidmahe Gopijana Vallabhaya Dhimahi Tanno Gopalah Prachodayath.

For Radha it is:

Om Vrishabhanujayai Vidmahe Krishna Priyei Dhimahi Tanno Radha Prachodayath.

For Sri Rama:

Om Dasharathaya Vidmahe Sita Vallabhaya Dhimahi Tanno Ramah Prachodayath.

Answer 2

Mahanarayana Upanishad

purushasya vidmahe sahasrakshasya mahadevasya dhimahi | tannorudrah pracodayat || 22||

tatpurushaya vidmahe mahadevaya dhimahi | tanno rudrah pracodayat || 23||

tatpurushaya vidmahe vakratundaya dhimahi | tanno dantih pracodayat || 24||

tatpurushaya vidmahe cakratundaya dhimahi | tanno nandih pracodayat || 25||

tatpurushaya vidmahe mahasenaya dhimahi | tannah shanmukhah pracodayat || 26||

tatpurushaya vidmahe suvarnapakshaya dhimahi | tanno garudah pracodayat || 27||

vedatmanaya vidmahe hiranyagarbhaya dhimahi | tanno brahma pracodayat || 28||

narayanaya vidmahe vasudevaya dhimahi | tanno vishnuh pracodayat || 29||

vajranakhaya vidmahe tikshnadam shtraya dhimahi | tannonarasim hah pracodayat || 30||

bhaskaraya vidmahe mahaddyutikaraya dhimahi | tanno adityyah pracodayat || 31||

vaishvanaraya vidmahe lalilaya dhimahi | tanno agnih pracodayat || 32||

katyayanaya vidmahe kanyakumari dhimahi | tanno durgih pracodayat || 33||

pathabhedahcaturmukhaya vidmahe kamandaludharaya dhimahi | tanno brahma pracodayat ||

adityaya vidmahe sahasrakiranaya dhimahi | tanno bhanuh pracodayat ||

pavakaya vidmahe saptajihvaya dhimahi | tanno vaishvanarah pracodayat ||

mahashulinyai vidmahe mahadurgayai dhimahi | tanno bhagavati pracodayat ||

subhagayai vidmahe kamalamalinyai dhimahi | tanno gauri pracodayat ||

navakulaya vidmahe vishadantaya dhimahi | tannah sarpah pracodayat ||

The answer given by Rickross is from the Linga Purana, but this is Mahanarayana Upanishad, so it has a few differences in mantras, though they may look the same apparently.