Anthrax information from the CDC: http://www.bt.cdc.gov/agent/anthrax/needtoknow.asp
Smallpox information from the CDC: http://www.bt.cdc.gov/agent/smallpox/disease/
Biological diseases/agents listing of the CDC are classified into three categories (A, B, and C) based on the severity of the threat.
Journal of Emerging Infectious Diseases: a list and links to articles on biological weapons: http://www.cdc.gov/ncidod/EID/bio_links.htm
You should read the last two articles.