The NOTEBOOK Madrid.comExpert facts from local expats since 2001
Moving to Madrid
Universities

Choosing Your University
If you go through the Erasmus program, the procedure is simple. You can select from the list of partners in your current institution universities. Registrations are through the Erasmus department of your university. 
If you do not go through an exchange, you must enroll directly in the university of your choice. For International students to gain admission to an undergraduate program in a Spanish University, they are required to obtain official recognition from their previous school.  Sometimes, you must also pass an entrance exam (Selectividad) which are offered twice a year. These exams are offered in several countries of origin for many of the international students. 
If you do not enter in the first year, the harmonization of academic qualifications at European level allows you to get an equivalence. 
After high school (el Bachillerato), the first university degree is Diplomatura (equivalent to Undergraduate). The Licenciatura (bac +5) is generally considered a Masters. Finally, Doctorate (2 or 3 years after the Licenciatura) is equivalent to the Doctorate. 
The academic calendar in Madrid can vary between schools.  Classes usually begin in September or October and finish in May or June.  Exams generally follow a week or up to month after classes end.  Also, retakes for exams will be held at different times after classes end.
Whether public or private, several Madrid universities are highly regarded. According to the 2012 ranking by the newspaper El Mundo, the Universidad Autonóma de Madrid is ahead for medicine. 
In terms of "overall quality", the Universidad Complutense de Madrid (UCM) is number one. It provides degrees in scientific and social science, law, economics, etc...
It is followed by the Politécnica de Madrid (engineering program). 
The top 3 business schools in Madrid are the Universidad Carlos III de MadridUniversidad Autonóma de Madrid and Pontificia de Comillas Madrid.

The registration fee at the university can be high depending on the chosen sector. If you do not participate in an exchange program, be aware that a year cost 500€ to 1,000€ in public universities and 5,000€ to € 10,000 for private universities.

Common Public Universities:

Universidad Autonóma de Madrid
Universidad Complutense de Madrid (UCM)
Universidad Carlos III de Madrid
Politécnica de Madrid
Common Private Universities:
Universidad Comillas Pontificia (ICADE)
University of Saint Louis
School of Management and Marketing (ESIC)
European University of Madrid (UEM)
Universidad de Alfonso X (UAX)
This website has a good list of schools, as well as other information:
www.altillo.com/universidades/universidades_esp.asp