A complete authoritative book on the life of Prophet Muhammad (S) by Sheikh Safi-ur-Rahman al-Mubarkpuri. It was honored by the World Muslim League as first prize winner book. Whoever wants to know the whole life style of the Prophet in detail must read this book.
Author: Saifur Rahman Al-Mubarakpuri
Why I Chose Islam: A story of a priest who reverted to Islam, it is based on a True Story.
Author: M. Emery
Publisher: Islamic Propagation Office in Rabwah
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
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.
A small but beneficial treatise concerning innovation, celebrating the birth of the Prophet (s), as well as a small note about Wahhabiyyah and the creed Muhammad bin Abdul-Wahhab.
Author: Abdul Aziz bin Abdullah bin Baz
Source: http://www.islamhouse.com/p/1267
The Muslim Creed - 'Aqeedatut-Tahaawiyyah.
Author: Abu Jafar at-Tahawi
Translators: Suhaib Hasan AbdulGhaffar