Once you have your flash file or image uploaded, you may submit it to be reviewed at the forums.
If you plan on being a regular artist, you should sign up for an account on the forums. In fact, you get a ton of extra stuff if you sign up for the forums, especially if you want to be able to edit your submission or submit more than one thing.
Once you sign up, you can get your own forum to discuss your work or anything you want, along with an RSS feed for members to subscribe to your work. Or, you can just have your work shown on the site.
For more details, go to the Submit Content page on FlashStuf Help.