There are several Geneva Conventions and Protocols, mostly concerning human rights and war crimes, but some on other subjects. The U.S. is a party to many (if not all) Geneva Conventions.
The International Committee of the Red Cross posts the text of the 1949 Conventions & Additional Protocols. Addition information is available at http://www.icrc.org/eng/war-and-law/treaties-customary-law/geneva-conventions/index.jsp.