Well here's a good starting point
wide angle advice
You'll get quite a few members rate the
Sigma 10-20mm, including myself. For pure quality , the Nikon 12-24mm is a cracking lens, but it does cost a fair amount more than the Sigma. The extra 2mm at wide end of Sigma also equates to an extra 10 degrees view.
I'm sure others will drop in their views soon
