patch submission procdure

This is a fairly dumb question, but is there a documented procedure
somewhere for developing and submitting patches? I had developed a
patch a few months ago to allow people to set the legend properties in
the rc file. It seems this didn't make it into the current version.
I recently got an email from someone wanting this feature as well, and
I told them I would follow through with it.

Part of the problem is that I don't have much experience with cvs/svn
beyond checking code out. That is why I am asking for a procedure. I
also don't know if someone needs to look at what I have done and make
sure I am not a total hack (I made some changes to it based on John's
feedback). I will in no way be offended if someone wants to look over
my shoulder, and I don't mind tweaking it to follow better coding
practices or whatever, but I do want to follow it through to getting
it included.