Several legendary figures from the MS-DOS and sizecoding scenes got together to bring you sizecoding.org, a wiki about x86 sizecoding.
I've only delved into it a little bit, but from what I've seen I can say that there's already a wealth of information there, and it's extremely well presented. Plenty of good stuff both for size-coding beginners and advanced x86 cracks can be found.
My only hope is that eventually some content about sizecoding on non-x86 platforms will be added. Well, seems anyone can sign up for an account there, so it's possible... In any case, massive props to trixter, HellMood, and qkumba for this excellent project!