Ramana MaharshiThe mind, turned outwards, results in thoughts and objects. Turned inwards, it becomes itself the Self (God). To ask the mind to kill the mind is like making the thief the policeman. He will go with you and pretend to catch the thief, but nothing will be gained.

Ramana Maharshi

Tattva Bodha
Knowledge of Reality, by Śaṅkarāchārya

Tattva Bodha Reference Materials:

Video/Audio Lectures

Swami Paramarthananda
36 classes (~30 - 55 mins each) 1, 2

Swami Anubhavananda
7 classes (~75 mins each)

Tattvabodha English 2 of 7 @ Prem Puri 2012

Swami Sarveshananda
27 classes (~45 - 60 mins each)

Swami Swatmananda
22 classes (~60 - 90 mins each)

20 vedanta fundas- full session with meditation

Swami Narasimhananda
12 classes (~60 - 90 mins each)

Introduction to Vedanta Tattvabodha Narasimhananda 2

Swami Viditatmananda
9 classes (search for "Tattvabodha" on the linked page)