Cox P. Introduction to Quantum Theory and Atomic Structure 1996

Textbook in PDF format

Clear and great insights into Quantum theory
From the very begining I had feelings to read and get clear insights into what is this quantum theory about. This book gave me full satisfaction. I liked it so much that I almost wrote the full book in my notebook, so that I may read it again and again ! (I had borrowed it from Chicago Public Libray).
The book's hallmark I feel is the simple on the dot language and comments that clears any doubts you may have. What I also liked is that it begins with the concept by first introducing the classical mechanics model and then emerging into quantum model.
Excellent book, all interested in the subject must read, to build a strong foundation !