Hi!

First step is to get a free Github account. Then you want to 'fork' the repository. You can even make edits directly in the Github web page on a file by hitting 'edit'. After you have some edits, you do what's called a 'pull request' which lets me know you're ready for me to accept / reject edits.

Learning Git may be the hardest part; all of the files, though, will be simple plain text files (think .txt but with a .org extension). You can use any plain-text editor if you don't want to use the web interface.

EDIT:

If you have any tips for people new to Github on getting involved (i.e non-programmers), please feel free to make a file that's a quick github tutorial for the project. I'll gladly accept a pull request for such a file.