Imam Hasan bin Ali 
An online book offers a biography of the second Imam, grandson of the Prophet Muhammad; covers in detail the treaty he signed with Mu'awiyah.
http://home.swipnet.se/islam/imamhassan.htmHassan
Profile of the Second Imam, son of Ali and Fatima, grandson of the Prophet; from the Encyclopedia of the Orient.
http://i-cias.com/e.o/hassan.htm
Imam Hasan
A collection of articles and audio resources about the Second Imam, from a Shia perspective.
http://al-islam.org/topical.php?sid=305657393&cat=92
