Hi Liddington,

Firstly, if you are in liddington nr.Swindon may I say hello, you are in one of my favourite places...I have friends there! Now, south facing, acid, clay.....that's the same soil I have here in Angus. Better question would be what plants can't i grow? There are sooooo many great plants you could grow. Ask yourself what plants you would like to grow, and then find out if they will tolerate acid and clay!
This website has a great encyclopedia that you can use to find lovely plants and inspiration. Gardening can be a bit daunting if you are a newbie, but if you've joined this forum you will get loads of advice, encouragement and inspiration! Go for it! :)) Karen

A great many plants is the answer - suggestions above are good, find plants you like, work out if they'll like your soil before buying.