If you don't know what pair programming is, read this: http://c2.com/cgi/wiki?PairProgramming
Bill Binkiewicz is one of the many top-notch developers at my office. He's also a pretty humble guy, and as far as I know, doesn't blog. He didn't even put his name on this, but that's OK - I'll add it for him.
I'm finding this to be a very useful model on my current team. The document centers around how to choose who should pair on a given problem, based on their interest and experience with the technologies and business domain.
Shared on my google docs site: https://docs.google.com/leaf?id=1UceBMcwGD8QDsLV5zEsUqhI-Baon9FSdQ1GhEHvM5OPnNwGNfkqff48ktHlX&hl=en