There is no real documentation yet, which is unfortunate. "rebar -c" is pretty helpful for what commands it has, and most of the layout conventions are not rebar's, but OTP's (those are documented here: http://www.erlang.org/doc/design_principles/applications.htm...). A rebar.config.sample file is provided in the GitHub repo which lists every configuration option. The mailing list and its archives are also pretty useful if you get stuck.