This is a useful book although it is small. It contains some technical terms for da'wah in English. No doubt all scholars and callers to Islam in English are in much need to something like that to conveys the right message of Islam to all those speak English.
Brief guide concerning the fundamentals of Islam.
Author: Naasir Bin Abdulkarim al-Aql
Source: http://www.islamhouse.com/p/1295
Time management from Islamic and Administrative perspective
Author: Khalid Aljuraisy
Translators: Muhammad Atif Mujahid Muhammad
Publisher: Al-Juraisi Foundation - http://www.alukah.net - Al Alukah Website
God in Christianity... What is His Nature?: The intent of this work is to honestly and sincerely present the truth that was found
Author: Naji Ibrahim al-Arfaj
This treatise was prepared by the Agency of Islamic Enlightenment in Hajj. Includes a discussion about those things which nullify a person's Islam as well as common errors made by the commonfolk.
Author: Muhammad ibn Saleh al-Othaimeen
Source: http://www.islamhouse.com/p/1377
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