Here I shall note down the books that best helped me to understand Advaita in all its ramifications.
I Am That: Talks with Sri Nisargadatta MaharajThis book is a translation of the teachings of this great master recorded by a Western disciple. The message of Nisargadutta is profound, and yet direct. The message may seem cryptic, yet each word makes immense sense, and no reader can come away from the book unchanged.
The Circle of Fire: The Metaphysics of Yoga This is by far my favorite book on Advaita philosophy and practice. It explains what Advaita is in a particularly lucid manner, indeed I should say that I had never understood Advaita till I read this. It also then analyzes Advaita in relation to modern science and shows the synergies between the two. It then describes the practice of Advaita. All this in a simple straightforward language without any humbug that simply makes it unputdownable till you finish it.