Scanning photos (and slides) - "ultimate" settings, resolution etc

Hi,

I am about to scan about 50 photos for the following purposes: (1) to email to some friends, (2) so I have the original prints kind of "backed up" digitally, (3) because I plan to publish a couple of them in a printed publication with an article and contribute a couple of relevant photos to someone's book.

Please can someone explain what resolution I should be scanning at for an "ultimate" scan (so I can consider the job done, and don't have to go back and repeat the tedious exercise)?

• 450 dpi or higher?

• 100%?

• save as TIFF?

I really don't understand the scaling of dpi / vs inches and resizing photos etc. But I'm hoping I don't need to worry about that right now.

If the prints are in b+w, should i scan in colour?

A second question: I tried to scan some slides on a flatbed scanner, but whereas the slides are bright and vibrant, the scans just look dull and faded and lack clarity/detail. How can I convert my slide collection to digital without wasting a lot of time and making my slides look so bad?

Thank you for your help on this.