Ibn Taymiyyah said: "This (enjoining good and forbidding evil) is a duty that the entire Ummah is obliged to fulfil. It is what the Ulama know as an obligation of collective responsibility, if a group in society undertook to discharge it, the other members of this society are absolved from it. The entire Ummah is commissioned to undertake it, but if a group therein was responsible for discharging it, the rest of society is no longer obliged to undertake it."
Author: Sheikh-ul-Islam ibn Taymiyyah
Reveiwers: Muhammad AbdulRaoof
Translators: Salim Abdullah Marjan
Rulings concerning different aspects of the Adhaan.
Author: Abdullah Bin Abdur-Rahman AL-Jibreen - Muhammad Bin AbdulRahman Al-Areefi
Publisher: Memphis Dawah
Source: http://www.islamhouse.com/p/1287
The author said in its introduction, "Nothing offends more the Christians than to cast doubt about the doctrine of the Trinity, the fountainhead of their faith. Since I grew up as a Christian, I know by heart that it will surely injure a devout follower of Christianity something he knew as true. But to lend a blind eye when I know better is far from righteousness since I am bound by the God's Commandments to guide those mislead by the false doctrine. It is a basic right of every individual to know the truth that will lead him to the right path.
This book is one of the most important Islamic books which gives right answers about Christianity.
Author: Sheikh-ul-Islam ibn Taymiyyah
A detailed description of the Dajjaal as mentioned in various ahaadeeth.
Author: Muhammad Salih Al-Munajjid
Publisher: Islamic Propagation Office in Rabwah
Source: http://www.islamhouse.com/p/1361
The Islamic View of Jesus (Peace Be Upon Him), 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 be up on him, In the Light of Holy Quran and Sunnah.
Author: Imam Ibn Kathir