Just caught site of some good info on painting in WinForms on jfo's blog. In particular the posts off his old blog at http://www.martnet.com/~jfosler/articles/WindowsFormsPainting.htm and http://www.martnet.com/~jfosler/articles/UsingDispose.htm.
Otherwise... I'm trying to find some time to update RikWik so I can update this site and improve some things. There's a few bugs which I'm putting off fixing until I build an entirely new version of RikWik with a lot of stuff cleaned up. There is lots of activity on RikWik at QUT but unfortunately our versions have forked and I can't just use all the great work Tim is doing. Incidently, that QUT link includes downloads for full source of a slightly older version of RikWik which you can play with yourself. Like most stuff I'm involved in, it's released under a BSD style license so go for it! We'd love feedback or contributions. Unfortunately documentation is still lacking, but hopefully one day soon...