Islam: The Complete and Final Message to Man is a brief presentation of Islam defining its terms and teachings, followed by an advice to the Muslims and non-Muslims on following the path of the Righteous Predecessors
Author: Dr. Saleh As-Saleh
One of the works on this subject is his “al‐Fatwaa al‐Hamawiyyah” which he wrote as an answer to a question presented to him. In it, he was asked what the scholars and Imaams of the religion say concerning the Aayaat and the Ahaadeeth of the Si/aat, or the attributes and characteristics of Allah.
Author: Sheikh-ul-Islam ibn Taymiyyah
Rulings concerning different aspects of the Adhaan.
Author: Abdullah Bin Abdur-Rahman AL-Jibreen - Muhammad Bin AbdulRahman Al-Areefi
Publisher: Memphis Dawah
Source: http://www.islamhouse.com/p/1287
This book follow the Adadith (prophet sayings) in an attempt to trace their miraculous nature from a scientific perspective so as to pave the Sunnah's way into the hearts of Muslims and non-Muslims as well.
Author: Zaqlol El-Naggar
Publisher: Al-Falah Foundation, Translation, Publication and Distribution
Concept of God in Major Religions.
Author: Zakir Naik
A nice discussion of some important points needed by those callling to Islam
Source: http://www.islamhouse.com/p/1243