Here's my response to the questions about housing.
1. In my personal opinion, it's better to live in the cité universitaire (the dorms) than an apartment. for the following reasons:
a) It is much, much cheaper to live in the dorms: You pay 140 euro per month for a single room in the cité universitaire, as opposed to the 300-600 euro per month you will pay to live in an apartment. While it is true that the apartments can be a lot nicer (most of them are furnished and some come with ovens) and a lot bigger, I personally don't think the extra comfort is worth it when you consider how many plane tickets to foreign countries that money could buy.
b) You will hear more french on a daily basis if you live in the cité universitaire. In theory, if you wanted to live in an apartment, you could look for a french-speaking roommate. But in reality, the chances of finding one are very slim, because when you arrive in Aix, most french and francophone students will have already signed a housing contract. However, in the cité u, you will definitely meet at least a few native francophones. It's true that there are a lot of foreign students at the cité U, some of whom don't speak french very well. But it's also true that a lot of the foreign students are from countries like Morocco, Sénégal, and Guadeloupe, so they've grown up speaking french their entire lives. In fact, the best friend I've made here is from Bénin, and I met him because he worked for the dorm.
2. French dorms are very, very different from American dorms. The rooms are much smaller, however, there's a lot of shelf and storage space, so if you pack wisely you shouldn't have a problem. Another difference: you will have a sink AND a bidet in your room. What you do with your bidet is up to you--personally, I let my towel drip dry over it.
Unlike American dorms, there's no RA, and there isn't even really a front desk staff in your building. There's a night watchman who guards the building from about 9pm to 6am, and a staff of femmes de ménage. Every weekday, the femme de ménage for your hall will knock on your door to see if you're sick or not. If you say "ça va", she goes away; if you say nothing or if you're not there, she'll enter your room for about 2 seconds to see if anyone's there. I know this sounds like a gross invasion of privacy, but honestly, she doesn't do anything in your room. It's a cultural difference you have to get used to if you want to live in the dorms.
3. As far as common areas go, there really aren't any. There's a salle de télévision in one of the dorms, and a main entrance area, but that's about it.
A part from that, you'll notice that the bathrooms are unisex. And, like many toilets in France, there aren't toilet seats and there isn't toilet paper, so you'll need to keep your own stash.
As far as other facilities go, each hall has a small community kitchen composed of four hot plates, a large sink, and refrigerator lockers. There is a student cafeteria, but it isn't located inside the dorm you'll be staying at (the Cité Universitaire de Cuques)--it's about a block away, near another set of dorms called les Gazelles.
In one of the buildings at Cuques, there's a place where you can do your laundry. There's also one salle d'internet, but most of the time the computers are broken. In the rare case that the computers are working, there's usually an ungodly long line for them.
4. The apartments are located in the center of the historic district of Aix, near the shops, most grocery stores, clubs, bars, and the IEP. The dorms are further out, near the fac des lettres and the Parc Jourdan. There is one grocery store relatively close to the dorms--the big Casino. In general, it takes about 15 to 20 minutes to walk from the dorms to the center of town.
5. Your dorm will come furnished with a lamp, a desk, a mattress, and two chairs. It also comes with a blanket and a pillow, but both are kind of uncomfortable, so I'd recommend bringing your own stuff. Similarly, the apartments are usually entirely furnished. Most apartments should also come with cooking gear. Although the dorms do not provide you with any pots or pans, you can rent a kitchen set for the year for 15 euro. You will also have an opportunity to get free stuff left over from this year's students at the program office at the beginning of the year.
6. Like I already said, it is a lot easier to meet francophone people if you live in the dorms, so naturally, you're more likely to be fluent a the end of the year if you stayed at the cité u than if you stayed in an apartment. It's all relative, though. If you don't make an effort to talk to people, you could very well spend the entire year in Aix without making any native francophone friends--regardless of whether or not you stayed in the dorms.
I don't have any pictures of my room at the moment, but I can upload some relatively soon.