The Guru Stotras are a set of verses recited or sung in celebration and adoration of the guru. They are sung especially at Guru Purnima, the celebration of the guru.
The different variations of this ancient sanskrit text contain from twelve to fourteen verses, of which the third seems most popular, and is often sung or chanted repeatedly on its own.
Included below is one variation of the Guru Stotras, with a loose english translation, verse by verse.
akhaNDamaNDalaakaaraM
vyaaptaM yena charaacharam.h
tatpadaM darshitaM yena
tasmai shriigurave namaH .
Salutations are to that guru who showed me the abode-- the one who is to be known--whose form is the entire universe and by whom all the movables (animals) and immovables are pervaded. (l)
aGYaanatimiraandhasya
GYaanaaJNjanashalaakayaa .
chakshurunmiilitaM yena
tasmai shriigurave namaH .
Salutations to that guru who opened the eyes of the one blind due to the darkness (cover) of ignorance with the needle (coated) with the ointment of knowledge. (2)
gururbrahmaa gururvishhNuH
gururdevo maheshvaraH .
guru sakshaat paraM brahma
tasmai shriigurave namaH .
Salutations to that guru, who is the Creator (Brahma), Sustainer(Vishnu), and Destroyer(Maheshvara) and who indeed is the limitless Brahman. (3)
sthaavaraM jaN^gamaM vyaaptaM
yatkiJNchitsacharaacharam.h .
tatpadaM darshitaM yena
tasmai shriigurave namaH .
Salutations to that teacher who showed me the one to be known, who permeates whatever that is movable and immovable, sentient and insentient, (4)
chinmayaM vyaapi yatsarvaM
trailokyaM sacharaacharam.h .
tatpadaM darshitaM yena
tasmai shriigurave namaH .
Salutations to that teacher who showed me (by teaching) the pervader of all three worlds comprising the sentient and insentient. (5)
sarvashrutishiroratna
viraajitapadaambujaH .
vedaantaambujasuuryo yaH
tasmai shriigurave namaH .
Salutations to that guru who is the sun to the lotus of Vedanta and whose lotus feet are made radiant by the jewel of all Shrutis (Upanishads). (The guru is established in the vision of the Shruti and is the one by whom the Shruti blossoms forth.) (6)
chaitanya shaashva tashaantaH
vyomaatiito niraJNjanaH .
bindunaadakalaatiitaH
tasmai shriigurave namaH .
Salutations to that guru who is Awareness, changeless (beyond time), who is peace, beyond space, pure (free from raga and dvesha) and who is beyond the manifest and unmanifest (Naada, Bindu, etc.) (7)
GYaanashaktisamaaruuDhaH
tattvamaalaavibhuushhitaH .
bhuktimuktipradaataa cha
tasmai shriigurave namaH .
Salutations to that guru who is rooted in knowledge that is power, adorned with the garland of Truth and who is the bestower of the joy of liberation. (8)
anekajanmasampraapta
karmabandhavidaahine .
aatmaGYaanapradaanena
tasmai shriigurave namaH .
Salutations to that guru who by bestowing the knowledge of the Self burns up the bondage created by accumulated actions of innumerable births. (9)
shoshhaNaM bhavasindhoshcha
GYaapanaM saarasampadaH .
guroH paadodakaM samyak.h
tasmai shriigurave namaH .
Salutations to that guru; the perennial flow of wisdom from the one rooted in the vision of the Shruti dries up totally the ocean of transmigration (samsara) and reveals (teaches) the essence of all wealth (the fullness, freedom from want). (10)
na guroradhikaM tattvaM
na guroradhikaM tapaH .
tattvaGYaanaat.h paraM naasti
tasmai shriigurave namaH .
There is nothing superior to knowledge of truth; no truth higher than the truth, and there is no purifying austerity better than the truth; salutations to that guru. (11)
mannaathaH shriijagannaathaH
madguruH shriijagadguruH .
madaatmaa sarvabhuutaatmaa
tasmai shriigurave namaH .
Prostrations to that guru who is my Lord and who is the Lord of the Universe, my teacher who is the teacher of the Universe, who is the Self in me, and the Self in all beings. (12)
gururaadiranaadishcha
guruH paramadaivatam.h .
guroH parataraM naasti
tasmai shriigurave namaH .
Salutations to that guru who is the beginning and the beginningless, who is the highest Deity and to whom there is none superior. (13)
tvameva maataa cha pitaa tvameva .
tvameva bandhushcha sakhaa tvameva
tvameva vidyaa draviNaM tvameva .
tvameva sarvaM mama devadeva .
Oh God of all Gods! You alone are my mother, father, kinsman, friend, the knowledge, and wealth. You are to me everything. (14)
Thanks go to my friend Jayshankara for helping with the translation