Scanning in photos

Scanning - using the Scanner and Camera Wizard

• Scan a photo for the highest resolution for which the image will be used. Standard for video monitor is 72 dpi
• For printing scan at the same resolution as will be used as when printed (eg 300 dpi)
• Scanning at a higher resolution is acceptable, at a lower resolution is not
• Ensure any print, especially those with a glossy surface, are scrupulously clean. Any specks of dust, fibres, loose hairs will show up sharply on the resulting scans

(from Photoshop Elements 3 by Carole Matthews and Doug Sahlin)

But note:

A Note on Resolution: The vast majority of scanning projects require resolutions lower than 300 dpi. For example, scanning a photograph at resolutions higher than 150 to 200 dpi only produces a larger file, not more detail.

from Scanning 101 - All about digital images