If you only plan on using your images on the computer (ie - never printed) then you can scan them at 75 DPI - the most a computer monitor can display. Anything over that is overkill.

However, if you are scanning images to print - then you can scan them at 150 DPI. Which will work fine.

In the publising world we scan full color pages at 266 DPI and these are huge images.

I hope this helps. Any questions - just ask.

Keith