there is a very good classifieds section on the talk photography forum here -
http://www.talkphotography.co.uk/forums/index.php
good for buying as its mainly a UK forum
there is also everything you ever wanted to know by either searching or asking on there, they seem a pretty friendly bunch & happy to help
if you see anything you fancy cross reference it with
http://www.dpreview.com/
where you should find listings of all specs & even detailed in depth reviews including comparisons with similar models from other makers
let us know how you get on
oh & look into getting a
http://www.flickr.com/ account as its not just an image host there are all kinds of groups on there for particular cameras, styles of photography, countrys etc.... you name it............