You should be scanning at 300 dpi or more for it to be of photo quality. Somewhere, when you start your scan, a dialogue box will show up asking you what settings you want etc. Even if you have a fairly large file that's say, 8x10 but it's at 72 dpi it won't print nicely. This is good for posting art online because then pirates can't copy and paste your work or make illegal prints to sell but it looks nice enough onscreen.
