Colleges at Durham are different from those at Oxbridge in that no teaching is done in them, it is all centrally based, but even so choosing the right college for you is worth thinking about.
1. Take a look at the prospectus. Read through the section on the different colleges carefully, and see which ones appeal to you at this point. Take a look at the chart of facilities each college has to see if that would make any difference to you e.g. a chapel - although attendance at these is not compulsory.
2. Check out the university website if you haven't done so already and check out the college webpages there, they will give you a bit more of a feel for each college and see if you still like the ones you were interested or can narrow it down a bit more. Also see link to JCR websites they will generally have an FAQ for prospective students on college life and admissions information etc.
3. Think about what it is you want from a college. Do you want ancient buildings, to be in the centre of town and weird and wonderful traditions such as sit down formals whilst wearing your gown? If so then look at the "Bailey" colleges. These are the ones in the centre of Durham, along the so called Bailey. They are University (Castle), Hatfield, St. Chad's, St. John's and St. Cuthbert's Society. Hatfield and Castle both have "formals" where you wear a gown twice a week and the others have them fairly regularly.
If the thought of all this fills you with dread and you would definitely prefer modern accommodation blocks with a better chance of en-suite then have a look at the Hill Colleges, Collingwood, Van Mildert, Grey, St. Aiden's, St. Mary's and Trevelyan. They are up on the hill near the science site, about 15 minutes walk from the centre of town, and are seen as being much less bothered with tradition (although some of them will still have regular formals - check for details).
Don't be put off either group solely because of where your course subject is situated (look at map in the prospectus). Durham is such a small city that nothing really takes that long to get to. There are always people walking backward and forward between the town and the science site for company and it's a great way to get chatting to someone from a different college/course that you might not otherwise meet. So it doesn't really matter where your favourite college is situated to be honest. The colleges all have quotas for certain subjects so there will generally be someone else around doing your subject even if it is in a college a distance away from the department. Hild Bede separate from the rest and is at the other side of town from the science site (although right next to the department of Education). It is generally seen as more isolated than the rest of the colleges but is the largest (over 1000 people) and even boasts its own cinema!
4. Think about whether you would prefer a large or small college. A small college e.g. Chad's will provide a close knit community but could feel really claustrophobic to some, whereas in a large college (e.g. Hild Bede) you might never get to know all the people in your year, or conversely find that there is enough of a community to have a large group of friends but not feel overwhelmed by the number of people at uni. Keep in mind both that much of your socialising is done in college and many of your nights spent at the bar so it's good to find one that you would be comfortable with. A small college might also spur you on to joining DSU based activities meaning that you make friends out of college as well as in, which is a plus.
5. Don't entirely base your choice on the stereotypes that are made out from talking to friends and looking at university guides. Yes the Bailey colleges are seen as more traditional and may perhaps attract a more public school applicant pool as a whole, but to be honest does it really matter that much to you? What kind of school you've been to really has no bearing. Remember everyone is in the same boat when they come to uni, talk to them, you never know, they may be really nice!
Hopefully you have now been able to narrow the choice down to one or two.
6. Do not be put off by the application ratios for different colleges e.g 16:1 for castle. To even be considered by the college your application must first been accepted by the department for your subject. This means that it isn't really 16:1 a place by the time departments have rejected a lot of people, plus colleges make many more offers that people they can fit in anyway. If the department accepts you and your chosen college doesn't then you will be put into a "pool" and passed around until a college has a space for someone on your course and makes you an offer. If the department accepts you then eventually they will find somewhere for you to live.
However, this is where it is important to have a personal statement that talks about your extra-curricular hobbies/interests, as colleges want people who will participate in community life and join societies etc. They already know you're a good person academically because the department has accepted you by then, so be prepared to really sell the fact that you could join the orchestra/rugby team/charity committee etc! That's the part of the personal statement they are interested in and enthusiasm for the non academic part of uni life will increase your chances of getting in to your first choice college, although it is no guarantee because they might have already fulfilled their quotas for your subject anyway.
Don't worry if that happens to you. Most people come to love their own college and are glad that they got pooled there. Each college takes a lot of pride in itself and has its own song etc.
Many people cannot choose or don't mind which college they will go to. In this case making an open application is a possible choice and the department will send your details on to a college that they think has room for you. However don't be fooled into thinking that this will give you a better chance of getting in to Durham as a whole. It doesn't, all it does it take out your option to state a preference as to where you live, you must still be accepted by the relevant department. Don't worry if you get up into St. Mary's, by 2007 entrance it will be completely mixed right through the years, although not any potential 4th years.
Good luck and don't stress out to much over all these things.
I have not included any information on George Stephenson or John Snow because I have never been to the Stockton Campus. The colleges are apparently fairly alike there and modern (2001) so choosing for character and facilities etc is not so important. However Snow is apparently very close to the shared College Bar (not so far to walk after a night out) and Stephenson, the larger college is next to the lecture rooms meaning not so far at 9.00! Take your pick.