Have a look at
Plusnet. Their basic package is £14.99/month, and there's all sorts of various activation options depending on how long you intend to stay with them. I have a Plusnet connection and have found it to be fast and reliable, and their customer service has been excellent (and you get to speak to someone in England that you can understand). Whatever you do, do NOT go anywhere near NTL, who are at the opposite end of the scale. I had them in my university house last year, and although the connection was usually OK the customer service, when needed, was an absolute disgrace.