www.talkphotography.co.uk is a site i would frequent quite a bit its pretty good lots of knowledgable individuals there.
Your best bet for a camera is either as you have picked out a nikon or a canon, when buying a new dslr you really are buying into a system. Both nikon and canon produce fantastic cameras and both have lots of varying lenses.
My biggest piece of advice is go to a shop and try out the different cameras, this will give you a feel for each of them as although the models are similar they do feel different and this will be the only real difference between systems.