1) Housing: If you choose to live in the dorm, you will have quick access to the faculties for Ciencias Sociales and Derecho: it is a five minute walk from your room to half of the department classes (it's a 15 minute walk to the IES center, where the mandatory IES Lengua class takes place). Also, you will have your lunch paid for on a once-per-day meal swipe (a worth of 6 euros) at one of three dining halls. The food is good, but absolutely forget eating there is you have food restrictions (like being gluten-free or vegetarian/vegan). Also, if you like healthy food like fruits and veggies, be prepared to eat lots of potatoes, plain iceberg lettuce, canned vegetables (or vegetables cooked with mystery meat) and other non-healthy food that they will claim is healthy! The dessert of any given day is your choice of a piece of fresh fruit or yogurt. As a dorm resident, you will have to pay for your breakfast, dinner and snacks. There is a small supermarket (El Dia) about 5 minutes away, and a larger all-purpose one (Marcadona) about 15 minutes away. There is also a small gym, study rooms on every floor, inexpensive wash/dry (4 euros per load), and a gaming room (billiards, tv, ext). If you are in a home stay: know that your food schedule is completely decided by your host family. The food is not always varied, but they are able to accommodate food allergies/restrictions. There is even a family that is great with providing food for those with Celiac-- the moral of the story is don't pick your housing based on food restrictions! As a student staying in a home stay, you also will have more of the money you saved/brought to spend on what you want (instead of what you need) because your host family will provide three meals a day and snacks. Be ware that host families can be a little overbearing and/or may not want you in their space-- they do not always consider you part of their families. Some students who lived in home stays were not allowed to be anywhere in the house except their rooms and the dining room (and especially not allowed in the family room where the tv was).
2) Internet: You need a connecter for the ethernet. Some laptops ave it built in, others you will need to buy a convertor for the thunderbolt (for Mac, not sure about PCs). The dorms do not have wifi in the rooms, but fast and reliable internet on the ethernet. You can also set it up so your computer emits wifi (just look it up) so you have it on your phone in your room. In the home stays it is hit-or-miss: some houses are great, others have spotty internet.
3) Walking: be prepared to walk everywhere. Two weeks after your arrival here in Salamanca, you will think a 20 minute walk is short. On average, I walked 6 miles a day in Salamanca without even trying. From the dorm to the IES building, it's about a 15 minute direct-route, downhill walk (nearby there is a dining hall). It is about 5 minutes to the Ciencias Sociales/Derecho faculties, about a 5 minute walk to the nearest dining hall, about 20 minutes to the Plaza Mayor, about 15 minutes to calle Van Dyck (a well-known, tapa bar street), and about 25 minutes to the Cathedral (and the plaza that has the Filologia/Language faculty). If you live in a home stay, it can be hit-or-miss. I suggest that you put location as one of your top priorities for housing because it will make your life much, much easier! No home stay was more than 25 minutes away from the IES center (which is about 5-6 minutes away from the Plaza Mayor).
4) Communication while in Salamanca: you are required to have a phone where you can be reached while in Salamanca with IES. Some students used their US phone and cell number. Others bought the Spanish SIM card (usually from a store named Orange) and added euros to it as necessary. Still others had two phones: their home one and a cheap (about 40 euro) flip-phone with a Spanish SIM card. Do what is best for you, but know that it is IES policy to have a working phone with you at all times!
5) Registering for classes: GOOD LUCK. The IES staff here are the least organized people. They also don't seem to care to help you, yet have all these obligatory/mandatory titles on everything. It was BS.
Overall, I loved my time, made great friends and got to travel plenty while still getting to know Salamanca but if I could do it all over again, I would do Madrid if I was studying in Spain.