Undoubtedly, the heart leans towards those who are kind and gentle. It was said a long time ago: "Make your face happy and your words gentle, and you will be more beloved to the people than those who give them a gift". The one calling to the religion of Islam and dealing with other people has the utmost need to gather the people around him, and cause their hearts to lean towards him so that they will listen to him. Adorning himself with kindness and gentleness helps to achieve that goal with the grace of Allah.
Brief guide concerning the fundamentals of Islam.
Author: Naasir Bin Abdulkarim al-Aql
Source: http://www.islamhouse.com/p/1295
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
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
The lofty rank and high station eemaan possesses is not something obscure, as it is unquestionably, the most important duty as well as being the most imperative of all obligations. It is also the greatest and most glorious of them. All the good in the world and the Hereafter is dependent upon the presence of eemaan and on its soundness and integrity. Eemaan holds such a multitude of benefits, ripe fruits, delicious pro-duce, constant food and continual goodness.
Author: AbdurRazzaaq AbdulMuhsin Al-Abbaad
Translators: Abu Safwan Farid Ibn AbdulWahid Haibatan - Abu Safwah Fareed Abdul Wahid
A brief but nice booklet discussing Zakaah, those items and amounts upon which it is due, and where it is to be spent. Includes a few important fataawa related to Zakaah
Author: Abdul Aziz bin Abdullah bin Baz
Source: http://www.islamhouse.com/p/1269