Report bugs: Be sure to mention Boost version, platform and compiler you're using. A small compilable code sample to reproduce the problem is always good as well.
Submit your patches as pull requests against develop branch. Note that by submitting patches you agree to license your modifications under the Boost Software License, Version 1.0.
Discussions about the library are held on the Boost developers mailing list. Be sure to read the discussion policy before posting and add the [rational] tag at the beginning of the subject line.