crackberry.com will cover you pretty well for anything the manual (which I've never ready anyway) falls short on.

Every BB has a unique PIN, and that's how you communicate with other BB users via Blackberry messenger (which can also be used for nifty things like sending another BB user a contact).

And some of the themes make the interface a little nicer. The Natemz themes which are free are my favs currently (I'm running his Pro 3 currently).