You might start by looking at this article we put together a while back:
Blogs at Splitcoaststampers
in general though, if you keep a few things in mind you should be okay. here's a few hints.
- use images in
jpeg format. this is the default format for most digital cameras and scanners
- use unique file names rather than the default your camera or scanner uses. For instance, try stampsetname_yourname.jpeg
- the gallery software will downsize any picture that is larger than 640 pixels wide or 480 pixels tall. you can upload something larger than that if you wish, but it'll get reduced.
- once uploaded, you can edit your photo (including replacing the picture itself) by clicking the Edit Photo link. you'll find this link on the gallery page for each photo.
Let me know if you have any further questions!