By "pro" do you mean SLR
Whilst I'm a Pentax fanboy, one of the cheapest dSLRs available is the Sony A230. Although, I suggest you read several reviews of any camera before buying.
Even if you don't intend to buy from them, I'd strongly recommend dropping into Jessops or Jacobs in Liverpool, so that you try one in your hand. Get a feel for the layout of the buttons. Make sure it's not too big or too small. Etc.
Be aware with dSLR, and the newer MILC
"bridge" cameras, that once you start investing in a lens system, to change away from that system can be expensive.
If the course does not require the use of a digital camera you will probably learn much more about aperture, ISO etc by getting a film SLR (fSLR?) to begin with. If you go down this route the Pentax K1000 or MX are ideal choices.