One of my favorite sites with tons of info is Radiant Vista. While strolling through their virtual bookshelves yesterday, I came across this very good tutorial on sharpening right here. It is nicely paced, easy to follow, and good information to know.
Mark Johnson goes through two very thorough descriptions in how he sharpens his images. One is the High Band Pass sharpening - but he throws a nice twist on the process. Also, stay tuned for his Elegant sharpening method, too. It's his favorite and works well. You will have to give it a minute or two to download, but hey, now you will have it on your computer for easy reference. Enjoy.
Hey gang, if you want some more great information on sharpening, then check out Thom Hogan's well written and very informative article on the subject right here - again good stuff.