You still can develop your negatives at high street chemists like Boots or photography stores like Jessops.
However is not cheap (at least compared to digital printing) and they will take a few days to deliver because negatives have to be sent to a laboratory.
You may better find small independent photography shops in every major and medium city of the UK in which you can buy analogic cameras, purchase film and where you can ask the best and cheapest way to develop your photos.

Yes, you can, but not many though. What I have found so far is that you can develope your camera film negatives via this site or maybe you can learn to do it by yourself.