I've done two Google Apps for Education roll-outs for schools recently and I can say overall it's been a very smooth process - the hardest bit is getting access to your school's domain for verification purposes as this is often controlled by the LA, unless you've bought your own domain of course. Google apps are definitely the best thing to happen to email since Hotmail. And the best bit is, schools get it for free! (minus any set up costs via a Google Apps reseller, of course )