RS232 / RS485 On 8-Bit AVR

Hey Guys/Girls,

I'm trying to get serial communications happening on an Atmega - basically I
was wondering if anybody knew of any good sites/books which explain this in
detail. I'm going to be writing in C.

I know a few people are going to say "Just google it" - which is what I'm
intending on doing as well, however, I thought this would be a great place
to start

Thanks in advance for your help

Cheers
Matt