Hi!
I've only known one person who studied there and that was in 1999, so I can't really tell you anything about the academic life, etc. However, I live near Villaviciosa, and I'd advice you to either look for an apartment in the village (very nice and quite place) or the city next to it (Alcorcón. Population: 175.000. It's got a university too - Juan Carlos I - and lots of pubs, discos and after-hours).
Alcorcón has metro stations (Line 10 and 12), train stations, bus stops and taxi ranks and it takes 10 minutes to get to P.Pío and 25 to the city centre.
I guess that you'll have some kind of meeting there and a short introduction. There should be an International Affairs Office where you may ask for help (mentors, tutors, etc) as well. You can also ask in the "Secretary" or go to the "Rector de Alumnos", but don't worry 'cos people here are very friendly so you can ask any student and they'll help you for sure.
U.E.M. Alcorcón
City Hall The City University