Barnsey, as Yeti's said, the DSC day is probably the best way to try out a track day before taking on a commercial day.
If you've never been to a trackday before, and are worried about being a bit slow jump in the novice group. If you're finding yourself quicker than the rest of the group and "getting stuck in traffic" you can always ask to move up (if you're not asked.....). Last year was the first time I went out in the Inters group with any TD organiser, so there's no rush to get out of Novices.
Brands Indy's a short circuit that should be quick to learn, but has some fantastic bends, especially Paddock Hill
If I didn't have to be at Southampton Airport tomorrow afternoon, I'd be there.
Don't forget, if you do go along, but don't take the bike, you can always borrow one of Ducati UK's bikes for a session or two.
[Edited on 4-10-2005 by Mr_S]