Jenn posted a really good sticky in the Announcements forum which can be found
here. In it is a link to a few more tips. When you upload your photo, just choose the main stamp set in your design from the dropdown list. This is very important, and makes life a whole lot easier for the SCS team because they don't have to spend time sorting the uploads into their proper places. Do not add it to your own gallery -- that will be created automatically with your very first upload.
Once you've uploaded your image(s), they have to be manually approved by a member of the SCS team. This can take several hours, as they have full-time jobs and families, so if you don't see it for a while don't worry, you didn't do anything wrong. It's usually there by evening if you uploaded early in the day.
Hope this was what you were looking for, and happy uploading!