Congratulations on this year and for qualifying for 2009.
See this link (bottom of page) for an explanation of the classes.
http://www.petplanet.co.uk/petplanet...og_showing.htm
You can enter more than one class, depending on qualifications, but you might want to check out the show schedule which is due out in September (I think) to ensure your entries don't clash timewise. Also keep in touch with the Kennel Club to check out any changes in classes - there was some talk about tweaking the limit and mid limit classes a bit if you're interested in those.