Hi Stu,
right then.....first things first. What kind of biking are you wanting to get into, and how much do you have to spend.
Aside of that. I'd go for a simple 'All Mountain' bike, which are for sale everywhere. Unless you're looking for something new and shiny, i'd get on ebay and have a look at some second hands ones. My reasons are...
a) There are millions of them about, for every price range.
b) as the bits break, buying news parts will introduce you to how the mechanics of the bike work.
c)you're going to break bits here and there, whether you like it or not. Inc your face if you're opting for downhill. So it's better to start off cheap on the bike and use the rest of money to buy some protective gear. Saftey first kiddies!

Hope that kind of helps.