It really depends on the kind of person you are as to which hall you choose. The main choice is whether to go catered (you get 3 meals every day) or you go self-catered (you buy and cook your own food, usually living in a flat with other people and sharing a kitchen).
I'd suggest that if you're more of a social person, enjoy being around people, go catered because you'll have the opportunity to meet hundreds of new people and hall events are great - it's like a bit of a community! (Obviously I'm slightly biased, I was in catered, hehe
) There are 12 catered halls on University Park - Hugh Stewart and Cripps have a reputation for being the 'public school' halls, and I think Florence Boot and Nightingale are meant to have some of the nicest rooms, but the best way for you to find out is go on an open day. Oh, and also you get a lunch card loaded with money which you can use Monday-Friday at all the cafes on campus
If you're looking for a more independent experience then look into self-catered (Broadgate Park, Raleigh Park, St Peter's Court). The upside is that you can eat whatever you want whenever you want, so you're not restricted to hall times and menus for eating. This is also better if you're vegan/have lots of allergies, but catered halls are generally OK for vegetarians. I've heard the cost of living generally equals out at about the same as catered halls as well.
I notice you asked about the housing system too - so, in about January of your first year you get together with a few friends (between about 3-8, it varies!) and you organise with a letting agent to go and view houses. Once you've decided which house you like best, you sign a contract with the landlord, and moving in is just before the start of first term in second year. No need to worry though, they talk you through it all in your first year, everyone's in the same boat and it's quite fun really
Main student area is Lenton, some people live in Beeston and Dunkirk where the prices are usually cheaper.
If you've got any more questions please feel free to ask (I'm a Nottingham 2nd year).
P.S. Congrats on getting it! Deffo the best uni