I just found this website the other day; North American Insects and Spiders - Cirrus Digital Imaging. There are tons of good resolution creature images in there and some good descriptions too (like the June Beetle's forelegs are adapted for digging. Excellent news!) Anyways, as I mentioned the other day that I was in need of bug reference, this is a sure good start.
Here's a June Beetle from www.cirrusimage.com. I think it is dead in this picture, but it probably lived a happily buggy life.
The one downside to this is I don't like drawing from photographs. Since I haven't done too much life drawing lately I may have a rocky start, but nevertheless full steam ahead. Until we get some thaw and the real deal is crawling around outside I'm stuck with bug photos. A minor downside.
What's cool is the collection is all creative commons licensed. I don't know the specific ins/outs of the page but I think you're allowed free use of the images so long as it's not for profit. Woo, pretty cool. Copyright laws are getting a work around lately and creative commons licensing is an interesting beast of the times. I don't know if I would release anything of mine under cc, but it's cool that it exists.