A nice discussion of some important points needed by those callling to Islam
Source: http://www.islamhouse.com/p/1243
The Fatawa's of Shaikh-ul-Islam Ibn Taymiyyah (Rahimahullah). Though he preferred the Hanbali school of jurisprudence, he was never biased in favor of it, he frequently quotes the opinions of all four of the well-known schools of jurisprudence, even others. In a number of matters, he himself held opinions different from those of the four schools.
Author: Sheikh-ul-Islam ibn Taymiyyah
This book gives a clear explanation of the Muslim sound Creed which is the core of the religion of Islam, as the belief in Tawhid (monotheism) is the purpose for which Allah created both mankind and jinn, and thus, those whoes belief in Tawhid is corrupt, are not considered Muslims.
Author: Saleh Bin Fawzaan al-Fawzaan
A book shows the importance of these ten days and the excellence of deeds in them.
Author: Muhammad Salih Al-Munajjid
Publisher: Islamic Propagation Office in Rabwah
Source: http://www.islamhouse.com/p/1355
Jesus and Christianity In the Perspective of Islam: This book guides those who misunderstood the teachings of Jesus and Christianity in the Perspective of Islam.
Publisher: Ministry of Islamic Affairs, Endowments, Da‘wah and Guidance
The book contains detailed information and descriptions that show how the Bible was changed and tampered with over the past two millennia. The account and the discussions presented are based on, and collected from, the writings of Christian authors, the Church and the Bible. By Misha'al ibn Abdullah