Seeing Louie's excellent tutorial post reminded me about a couple of tutorials that I produced for AAIC. Many times when I prepare for a presentation I produce a tutorial for it and build the powerpoint file from it.
If you attended AAIC then you have a DVD copy of these but for those who may be interested, I have posted them on my site.
The first is an 8 chapter tutorial covering everything from sharpening - masking with alpha channels and my favoite methods for boosting color.
The 2nd is an introduction to the amazing new tool in Photoshop CS5 - HDR Toning tool.
They are Flash movies and require fast internet. If anything you can use them to get more sleep