Kitab At-Tawheed is one of the best books on the subject of Tawheed (Islamic Monotheism) and ranks high in authenticity. Till date it has gone through various publications; and had been the means for guidance of the millions of people throughout the world; by taking them out of the darkness of polytheism and error.
Author: Muhammad Bin Abdul Wahhab
Publisher: http://www.islambasics.com - Islam Basics Website
The "Islamic Studies" series of books by the prolific writer and scholar Dr. Bilal Philips are part of a meticulously written series intended to guide young Muslims in a manner that helps them acquire a thorough practical and spiritual foundation. This series have been generally acknowledged as an excellent introduction set to the principles of the Islamic faith, with core sciences discussed and explored, for both the new Muslim as well as the "old" Muslim wishing to brush up on the fundamentals.
Author: Abu Ameenah Bilal Philips
According to Biblical scholars and the text of the Bible itself, Shaikh Ahmed Deedat explained in detail regarding "Is the Bible God's word?"
Author: Ahmed Deedat
A proof that the Qur'an is from God and that Muhammad is a Messenger of God.
Author: Abdullah Bin Abdur-Rahman AL-Jibreen
Publisher: Memphis Dawah
Source: http://www.islamhouse.com/p/1285
Dr. Saleh As-Saleh shows in his introduction to this book that Allah could not have created this universe without a purpose. He is All-Wise, All- Knowledgeable, All-Merciful and All-Just. All of these attributes entail providing ways of guidance that would lead to the proper knowledge of Him, and thus the right way to worship Him. Allah sent his messengers to direct man to relate to His Creator through complete submission and obedience (this is the meaning of Islam). He needs to know what benefits him and what harms him. The Message from Allah comprehends everything. It brings man to live for a noble purpose. All forms of worship are explained in the Qur'an and by the Prophet. Worship is not left for our limited minds to decide upon their ways.
Author: Dr. Saleh As-Saleh
Publisher: http://understand-islam.net - Understand Islam Website
An excellent book for non-Muslims explaining various aspects of Islam.
Author: Pete Seda
Publisher: Islamic Propagation Office in Rabwah
Source: http://www.islamhouse.com/p/1301