Two sites with detail about all things Nikon:http://www.bythom.com/index.htmhttp://www.dpreview.com/
(you will need to join to access anything useful)http://www.nikonians.org/
If you live in the US do not buy any new Nikon stuff that is not US-spec as you will never get any support or warranty service from Nikon. Most Nikon products have a serial number that is specific to where it is intended to be sold.
Also be careful about who you buy from as Nikon may refuse to support purchases from a non-authorized vendor.