I am a developer and I feel that I can't design myself out of a paperbag sometimes. I was wondering if there are any books or sites that I can look at to improve my UI design skills?
I'm a designer and I can tell you the following: Don't be fooled by anyone who tells you that you can learn everything about usability or design in general after reading one book.
If on the other hand you're looking for a starting point I'd recommend "Don't Make Me Think: A Common Sense Approach to Web Usability" by Steve Krug.