Sahih Muslim includes sayings, doings and approvals of the Prophet Muhammad (peace be upon him) narrated by his companions. It is considered the third most authentic book in Islam after the Quran and "Sahih al-Bukhari". It covers almost all aspects of life.
Author: Muslim ibn al-Hajjaj ibn Muslim al-Qushairi an-Naisabori
Translators: AbdulHamid Siddiqui
Publisher: http://www.islamspirit.com - Islam Spirit Website
Ibn Rajab al-Hanbali This is a treatise we have written concerning humility (Khushu') and the hearts meekness and breaking (inkisar) before the Lord. The basic meaning of Khushu', is the softness of the heart, its being gentle, still, submissive, broken, and yearning. When the heart is humble, so too is the hearing, seeing, heard, and face; indeed all the limbs and their actions are humbled, even speech. The source of the Khushu, that takes place in the heart is the gnosis of Allah's greatness, magnificence, and perfection.
Author: Ibn Rajab Al-Hanbali
A brief but nice booklet discussing Zakaah, those items and amounts upon which it is due, and where it is to be spent. Includes a few important fataawa related to Zakaah
Author: Abdul Aziz bin Abdullah bin Baz
Source: http://www.islamhouse.com/p/1269
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
The book contains detailed information and descriptions that show how the Bible was changed and tampered with over the past two millennia. The account and the discussions presented are based on, and collected from, the writings of Christian authors, the Church and the Bible. By Misha'al ibn Abdullah