Remember also that anything posted to the network is 'out there' effectively and thus beyond your control. The best you can do is to put some sort of request on your art or story to request people avoid redistributing it or modifying it in any way. Even then, you may find your stories or artwork from years ago haunting you as well-meaning people repost them. In addition, you might have some luck with alt.prose and alt.prose.d.
Several MUDs hold writing circles.
If you're interested in seeing your story in print, look up the 'zines list. In addition, there is now a Web site that points to various furry stories around the World-Wide Web. Artwork must commonly be posted in an encoded format, a practice which is frowned upon in any primarily-text newsgroup. There are some excellent FAQs on art materials and techniques for the preservation of artwork. If you're looking for tips on drawing anthropomorphics, however, you will certainly do best to ask for help on alt.fan.furry with your particular drawing style.