I've just finished my first degree at Durham and am moving on elsewhere now for a change having spent the last 3 years in Durham! I was at Mary's and if anyone wants to know anything, please ask me and I'll try to fill you in on anything you want to know.
When I first arrived in Durham, I was a little nervous and unsure of what to expect as I imagine you are feeling now? College was most welcoming and some of my closest friends I have now are those I made that first day I got there and we met other freshers over coffee I recall.
After the manicness of freshers' week, things soon settled down and I learnt that you get out of college what you put in it and the same can be said for all the Durham colleges. Many people didn't put Mary's down as their first choice, myself included and it is simply a case of making the most of things..college rooms are amongst the best in the university. I had a big room for every term in 1st year and never had to share...in 2nd year, the livers out facilities were very good indeed and we had a dedicated rep who looked after us all! Food is not at all bad..although everyone moans about it but if you are used to institutional food, you will probably be fine..it served me well!
Anyway, please get in touch if you have any worries..but just go with a positive attitude, that's my advice!