Kitab At-Tawheed is one of the best books on the subject of Tawheed (Islamic Monotheism) and ranks high in authenticity. Till date it has gone through various publications; and had been the means for guidance of the millions of people throughout the world; by taking them out of the darkness of polytheism and error.
Author: Muhammad Bin Abdul Wahhab
Publisher: http://www.islambasics.com - Islam Basics 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.
The testimony of "Laa ilaaha ill-Allah", its meaning, prerequisites, conditions, and fruits.
Author: Saleh Bin Fawzaan al-Fawzaan
Publisher: http://www.islammessage.com - Islam Message House Website
Source: http://www.islamhouse.com/p/1223
This is a small book in which it answers 32 questions through Qur'anic verses. It answers questions about Allah, the true creator, previous nations, meaning of worship, saving Quran from corruption, Prophet Muhammad and Prophet Jesus (peace be upon them), the Hereafter and destination of both believers and disbelievers.
Author: Mohammed Bin Yahya Al-Taum - Muhammad ibn Yahya Al-Toom
Hajj and Tawheed: Hajj is to set out for Makkah to worship Allah by performing certain religious rights in accordance with the Prophet's (peace and blessings be upon him) Sunnah. It is a time in which to call upon Allah to purify the self from any worship to anyone other than him. This booklet explains the basic rights of Hajj. It also notes that the tawheed of Allah requires the Muslim to follow the perfect way of worship, demonstrated by Muhammad (peace and blessings be upon him) and as understood by the Sahaabah who were the best of mankind.
Author: Dr. Saleh As-Saleh
Jesus in Islam: How did the Quran Narrated the stories of the messengers and prophets from Adam to Muhammad, and the Quran had explained in detail the story of Jesus peace up on him.
Author: Ahmed Deedat