Here's a 2 hour web seminar on Sharpening, by Andrew Rodney:
http://www.retouchpro.com/index.php?page=rodney
Mr. Rodney is the author of Color Management for Photographers.
http://www.digitaldog.net/
"Everyone knows that the Unsharp Mask filter can make your images sharper but are you using this tool to produce optimal sharpening? If you are conducting global sharpening of your images in Photoshop, not a chance. In this Webinar, we’ll cover best practices for sharpening your images using a workflow that takes into account capture, output and optionally, creative sharpening. You’ll see how sharpening in Adobe Lightroom and Camera Raw might provide a superior and more productive method of sharpening your images from capture to print. You’ll see the latest version of an yet to be released Photoshop Plug-In for simple one-click sharpening within Photoshop. You’ll learn how to sharpen without increasing noise and grain and how to target the optimal tonal range of your images for capture and output to devices from halftone to Inkjet, to screen."