Most scanned in images are very large on the screen. Your program that you use to view the image usually displays them at 33% of their actual size or so. That way "you" get a different view of the actual image. Using a drawing package like paint shop pro you can alter the size of the image.
If you haven't got a copy of a drawing package then I'm sure you can download one free from
www.download.com
I would make them about 400 pixels wide. That would be a reasonable size for viewing on the web. A JPEG would be about 50k at this size with a good resolution.
Regards
Vince
Time served Auto Electrician
Lucas Leeds 1979-1983