a fine writer, and his site is here: http://www.neildaniels.com
There are loads of other fine writers linked from his site but if I put them here there's less reason to visit Neil, which you should because he's a good man.

If I'm needing pics they need to be 300dpi jpegs (or TIFF) and the size at least 8" x 10" otherwise mag designers kick off at me all the time, and often pieces are in danger of getting spiked because of it. That's obviously not good for anyone.

The file size should be therefore well over 1 Meg and probably 2 Meg or more. If it ain't, it ain't big enough. Check it.

The quality of the shot, of course, is most important: Sharp, Clear, Fizzy. No Photoshopped filters neither - yuck yuck, no no. Bad.

Here's some info that I don't really get either, but anyway:

http://en.wikipedia.org/wiki/Dots_per_inch

http://www.fotofinish.com/resources/centers/photo/resolution.htm