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
Brief guide concerning the fundamentals of Islam.
Author: Naasir Bin Abdulkarim al-Aql
Source: http://www.islamhouse.com/p/1295
The Muslim Creed - 'Aqeedatut-Tahaawiyyah.
Author: Abu Jafar at-Tahawi
Translators: Suhaib Hasan AbdulGhaffar
This is a lecture that Shaikh Al-Albani gave in the city of Doha, the capital of Qatar, during the blessed month of Ramadan of 1392H. Then requesters asked the shaikh to print it due to the important benefits contained within it, and to the Muslim's need for something like it.
Author: Muhammad Naasiruddeen al-Albaanee
Translators: Abu Maryam Ismaeel Alarcon
Effects of fornication upon the self and society
Author: Muhammad ibn Ibraheem al-Hamad
Publisher: Daar Al-Watan
Source: http://www.islamhouse.com/p/1329
The Choice - Islam and Christianity: Two Volumes, By Ahmed Deedat, An excellent book discussing Islam and Christianity in the light of Holy Quran and the Sunnah.
Author: Ahmed Deedat