I can't imagine you needing any filters at all Paul. If you plan to do a lot of macro work a ring flash would be a big asset. I think Jessops do the Centon one for around 60 quid or so. You'd have to check on compatibility with your camera though. There were one or two going on ebay last time I looked.
Edit
I've just looked
http://cgi.ebay.co.uk/ws/eBayISAPI.d...56210&rd=1
There's some others.