Unmasking Muhammad is a book with a description of the psychological profile of Muhammad. It is written by Sujit Das. Chapter 1 is rather polemical but from Chapter 2 onwards the character of Muhammad is disected in a very detailed and scientific way. You can downloaden the book by clicking on the following link.
Below, you will find a list of books with recommended reading in relation to Islam.
A God who hates is the first book by Wafa Sultan. It explains her path out of Islam. She grew up in Syria and now lives in the USA. She is one of the founders of Former Muslims United, an american organisation of former Muslims. Her book can be ordered from Amazon in the following link.
Books by Robert Spencer, director of www.jihadwatch.org. Robert Spencer has authored an number of well-written and carefully documented books about Islam. You can order the books on Amazon on the following link.