Housing for Erasmus student

Im going on an Erasmus exchange in September 2015 and I am looking for a place to stay from September to the end of January 2016.

I am from Northern Ireland, speak English and learning portuguese.

I would prefer somewhere as close to the university as possible or city centre.

A single room is preferred but not necessary.

I am looking for a shared apartment with other students or a studio.

Please contact me if you can help!