Since mountain lion comes out soon, I wanted to codesign all my mac apps. But I have no clue how to do it.

I know I must use the commandline codesign tool since I can't use Xcode for my Ren'Py games, but apart that I am totally in the dark. I would also like to try submitting to the mac appstore even if probably they'll be rejected, but just to see what happens...

Anyone has a VERY SIMPLE STEP BY STEP guide? I tried looking at apple docs but there are 310983021 pages with insane geek talk and no way I can understand that babbling