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
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
The Scientific Miracles of the Quran
Author: Gary Miller
Publisher: Abul-Qasim Publishing House
Source: http://www.islamhouse.com/p/1407
The Hadith is Proof Itself in Belief & Laws
Author: Muhammad Naasiruddeen al-Albaanee
A nice discussion of some important points needed by those callling to Islam
Source: http://www.islamhouse.com/p/1243
The Fasting of Ramadan: a reference that simplified all matters pertaining to the fast and Ramadan in this short and concise treatise.
Author: Muhammad Jameel Zeeno