A most rewarding and fulfilling part of a Muslim's worship are those blessed moments that he spends praying in the depth of the night, privately addressing his Great Lord, sincerely glorifying Him, humbly imploring Him - beseeching His forgiveness and asking Him for favors. The voluntary "night prayer", or qiyaam, is indispensable for a person's moral, spiritual, and physical welfare. Yet, it is greatly misunderstood and largely neglected by most Muslims
Author: Muhammad Naasiruddeen al-Albaanee
Translators: Abu Maryam Ismaeel Alarcon
A nice discussion of some important points needed by those callling to Islam
Source: http://www.islamhouse.com/p/1243
A Book discussingthe importance of khushoo in prayer and how to achieve it
Author: Imran Hussein
Source: http://www.islamhouse.com/p/1401
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
The Needs Of Humanity In The Mission Of Prophet Muhammad: This is a research that was developed to answer the Westerners who presently asking what new aspects Prophet Muhammad -peace be upon him- offered to the world?
Author: Adel ibn Ali Al-Shiddy - AbdulRazaq Maash
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