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
These are three good books for learning Arabic Language for the non-native speakers. But we should pay your attention that they are for who has slightly good knowledge about Arabic and how to pronounce it. We don't claim that you can consider them as an alternative to a teacher but they are good step for who wants to be excellent at Arabic. With these books, there is an Arabic-English glossary confined to the words mentioned in these books, and the author shows in its introduction how to find any word.
A nice discussion of some important points needed by those callling to Islam
Source: http://www.islamhouse.com/p/1243
The Life and The Aqeedah of Muhammad ibn Abdul-Wahhab: This book is not one with a political agenda. It is meant neither to support nor to critique any contemporary regimes or policies. Indeed, the driving force behind this work is much greater and more important than that. It has to do with, first, the religion of Islam as preached by the Prophet (peace and blessings of Allah be upon him) himself and, second, with the honor and rights of an individual Muslim, Muhammad ibn Abdul-Wahhab.
Author: Mahmoud Reda Morad Abu Romaisah
Reveiwers: Muhammad AbdulRaoof
Publisher: A website Islamic Library www.islamicbook.ws
This is a translated transcription of a lecture delivered by Imaam Al-albaanee (rahimahullah) that was recorded and distributed under the title "Hadhihi Da'watunaa" (This is Our Call). The present translation was translated directly from the Arabic audio. In this lecture, Imaam Al-Albaanee explains the basis of the Salafee Manhaj, which is following the way, understanding and practical application of the Salaf, who ware namely the first three generations of Muslims: The Sahaabah, Taabi'een and Atbaa' at-Taabi'een. They are the ones referred to in the Prophet's saying: "The best of mankind is my generation, then those that come after them, then those that come after them."
Author: Muhammad Naasiruddeen al-Albaanee
Translators: Abu Maryam Ismaeel Alarcon
One of the most detailed books describing the rulings of Hajj, Umrah, and visiting the Masjid of the Prophet (peace be upon him).
Author: Sayid Sabiq
Source: http://www.islamhouse.com/p/1395