Turkish, I'm currently at the college and here's what i think....
Most people stay in bed and breakfasts to begin with. A pretty good idea as you may fail the course and be out of a job in 3 months, making even a 6 month tenancy agreement pretty dodgy. Some do have rented flats/houses on short term lease and others have gone for it and rented one for 6 months. You could never afford a 1 bed flat but sharing defintely possible.With the B@B's I believe they cost about £100 a week (some with evening meal as well) and they have the advantage of no bills to pay. The take home pay is just shy of £700 a month so it is possible to have some kind of life as well.
I don't think anyone on our course worked a 2nd job to supplement the income - it would be VERY hard to do with the workload at the college.