If you are interested in making/casting your own bullets, this is the best site of all to read first; After reading the Lyman cast bullet handbook; and the RCBS cast bullet handbook.
http://www.lasc.us/
After that, the silver stream erupts into a flood of info on these sites;
http://castboolits.gunloads.com/forum.php?
http://www.castbulletassoc.org/