Move People Around:
Pair Programming:
Some fun pairing rules (guidelines) you can print out and stick on a wall maybe once people have tried pairing for a few weeks:
Some lessons you can probably only learn by trying it first and seeing what works in your environment:
Dirty Secret
http://agilesoftwaredevelopment.com/blog/mendelt/dirty-secret-pair-programming
Ron Jeffries
http://www.xprogramming.com/Practices/PracPairs.html