A favourite of mine was the Cleevewold on 28 March
http://www.cheltenhamharriers.co.uk/..._info_2010.doc
It's on your way to work. Great views fom the top of the scarp. Big climb from 9 to 11 mile and a sneaky killer climb at 13 just when you think you're finishing.
Other keen clubs that way are Marlborough , Exeter, Bath and my old one at Pewsey.
Once you get to a race you'll find plenty of flyers advertising the next batch and probably another half dozen stuck under your windscreen wipers.