Since i'm now a Nikon user I'm looking for a good Nikon forum or a good photography forum in general...

We actually have a Digital Photography subforum here on Club Lexus. It is right below this forum (The Photoshop Forum)

Here's a screenshot, I've highlighted it in red



https://www.clublexus.com/forums/digital-photography-152/

Opps I posted this in the wrong place...

I know about that but looking for a bigger photography community.

This is my favorite one.
http://www.dpreview.com