IrfanView is free and quite capabile of adjusting colors, cropping and re-sizing chip scans.

http://www.thechipboard.com/cgi-bin/bbs521/webbbs_config.pl/noframes/read/910315

Irfanview - open the file, Image > Resize > for the web make it 800 pixels wide or less. (should be set for Retain aspect ratio which is the default) Save As (JPG of course), image quality 80 - New Name, so you don't lose the original image. Watch where you save it to. now you have a reduced size image.

This one is 640 wide and is hosted free on Imageshack. As you can see, 640 wide is plenty big!

Just go to Imageshack.com upload the image, highlight the second box, CTL-C (copy) come back and CTL-V into a message, add the image tags in front and back.

That's the easiest way, free editor, free hosting. Have fun!