We're about ready to submit ours for Counter Culture Labs. You can find tons of good info on http://form1023.org/ First thing to do will be to get your bylaws in order - the 1023 form (which is what you fill out for the 501(c)3 application) will ask you to quote specific paragraphs where various things are covered in your bylaws.

I have access to bylaws and 1023 forms from several organizations for reference, if someone wants to have a peak at them.

Patrik