They are the companions of the prophet Muhammad (peace Be Upon Him), they are the ones who stood besides the prophet (PBUH) through all the extremely hard times and good...they fought besides him in Jihad, and would compeltely agree with the judgements of the Prophet (PBUH)

they are so many...the main ones are:

1. Abu Bakr Siddiq (ra) >> http://www.islamicboard.com/biograph...st-caliph.html

2. Umar bin Khattab (ra) >> http://www.islamicboard.com/biograph...nd-caliph.html

3. Usman (ra) >> http://www.islamicboard.com/biograph...rd-caliph.html

4. Ali (ra) >> http://www.islamicboard.com/biograph...th-caliph.html

there is a section on this forum where you can learn more about these pious predecessors Insha'Allah

>> http://www.islamicboard.com/biograph...lamic-figures/



and you can download lectures by Imam Anwar Al-Awlaki on the life of Umar, Abu Bakr and also the Prophet Muhammad (PBUH) on the following link..

>> http://lectures.kalamullah.com/


and heres a good thread where you can download other beneficial lectures Insha'Allah

>> http://www.islamicboard.com/islamic-...a-allah-4.html (Lectures - MUST LISTEN! Insha Allah)