This has been asked 50 times at least, but anyways...
Open the shot with paint and use the stretch/skew to resize it to something smaller (you can google online to look for programs that can do this to many images at a time, and resize it to a specific resolution), after that, save it as a jpg somewhere, then upload it, I'd recommend
www.imageshack.us for maintaining quality and size. But do not use bmps as they take very long to load. Use jpg's or png's, preferably jpg's if you can get around the lossy quality.