Ramana MaharshiDo not doubt, with fear, what will happen when you completely lose your individuality [jiva-bodha]. The true State of Self will then Itself be yours, just as one will permanently remain firm on the ground when one loses one’s hold on the branch of a tree.

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)

02 Vedanta Fundas - Tattvabodh introduction-02

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)