Want to sell stuff on eBay? The picture makes all the difference in your final price.
Here are a collection of articles with enormously practical tips for taking professional-looking product photos.
http://pcworld.about.com/news/Oct142003id112658.htm >> General overview of taking the picture and applying perspective
http://www.graphic-design.com/Photoshop/extracting/index.html >> Talks about the "extract" filter -- a quicker, often better tool than the simple lasso tools
http://www.graphic-design.com/Photoshop/Tips/rotating.html >> An overview of Photoshop "actions" -- a system to automate removing backgrounds, applying the "auto-levels", or whatever else
http://www.betterphoto.com/forms/qnaAll.asp?catID=198 >> A Q&A-style forum with relevant questions and some very practical, simple advice (scroll down!)
http://www.connectedphotographer.com/issues/issue200407/00001331001.html >> Another detailed article with good suggestions for taking the picture right to begin with
Remember, when taking pictures for the web: high resolution is not that important. Good lighting is the most important thing!
(And, yes, I did post this just as a reference for me, someday.)