No matter what you read about ASP.NET routing or REST I think the best way to learn more about them is to read other people's routing files. In a video with Jeff once you could catch a glimpse of the stackoverflow routing file if you paused the video in the right place. I actually learnt quite a lot just looking at how it was organized.
To that end - does anybody want to post their routing data (in full or in part) from global.asax.cs for others to learn from? I'll post mine when its more organized - kind of messy now.
Tip: Not that you should have any security holes - but you might want to check that theres nothing 'secret' in your file before you post it.
Check here for mvc sample apps.