Before you scan your images, you might want to take a look at the following articles by Anthony Celeste. Tony talks about everything from choosing the proper scanning resolution to adjusting tone to the importance of sharpening your images.

Part I: Obtaining the Image - Use the best dpi for the job you're doing.

Part II: The Tone Map - Use Brightness adjustments to maximize the look of your image.

Part III: The Unsharp Mask Tool - Some helpful hints on how to best sharpen your images.