I find the RubyInline documentation pretty sparse - which is a shame and a hurdle. I suggest augmenting the documentation with this, which has been a great help to me (if one can get around license issues?):
See: README.EXT, ruby.h, intern.h. It isn't RubyInline's job to teach the internals of ruby. If you'd like, submit a pull request with links to relevant documentation and I'll merge it.
I find the RubyInline documentation pretty sparse - which is a shame and a hurdle. I suggest augmenting the documentation with this, which has been a great help to me (if one can get around license issues?):
http://www.eqqon.com/index.php/Ruby/Ruby_V1.9_C_Extension
Also, I suggest a cookbook like Perl's:
http://search.cpan.org/~sisyphus/Inline-0.48/C/C-Cookbook.pod