SDLdoc (The SDL Documentation Project) was formed to completely rewrite the SDL documentation and to keep it continually up to date. The team consists completely of volunteers ranging from people working with SDL in their spare time to people who use SDL in their everyday working lives.
The latest version of this documentation can always be found here: http://sdldoc.csn.ul.ie Downloadable PS, man pages and html tarballs are available at http://sdldoc.csn.ul.ie/pub/