http://www.pssathletics.com/ArticleW...enchPressI.htm
Check this out. A very comprehensive list of things you should do to improve your bench presss technique. There are actually two more parts, but I thought this one was the best.
The other two parts can be found here:
http://www.pssathletics.com/ArticleW...nchPressII.htm
http://www.pssathletics.com/ArticleW...chPressIII.htm
It was written by Tony Reynolds, a strength and conditioning coach. The site has a few interesting articles on it. I read the ones about biomechanics and periodization. There is also some nutrition stuff that I have yet to delve into.