A to Z of Asterisk

Hi
I am going to make assignment on ASTERISK but I need complete information for that. I have no much basic knowledge so please give name some resorces such as some website,books,articles etc.
Thanks.

Read the book: Asterisk: The future of Telephony
h6315.com/ast_docs/Asterisk%20TFOT%20v2.pdf

Have a look at the wiki:
voip-info.org

Good Luck.