Nikon D5100 Official site
You Can read many details and information about D5100 Review in their manufacturer site. Details like complete features, technical specification and etc.
http://imaging.nikon.com/lineup/dslr/d5100

D5100 Review on Wikipedia
In this wikipedia, you can browse the complete list of Imaging Nikon products, including Nikon D5100
http://en.wikipedia.org/wiki/Nikon_D5100