Two 21 years old studends looking for accomodation in Amsterdam

Hello! We are two guys from Barcelona going on Erasmus to Universiteit van Amsterdam next year (first semester).  

We are looking for an apartment in Amsterdam, as centric as possible, to rent from August/September to December/January (2016-2017). We are looking for something between 350-650 euros per person (bills included). We are flexible regarding the number of bedrooms and size of the apartment as long as there's room enough for two people. We are also willing to share the apartment with someone else if needed. 

We love the city and hope to blend in and get to know Dutch customs and lifestyle. We both speak fluent English, Spanish and Catalan and, hopefully, a little bit of Dutch once we finish our Erasmus journey.

Thank you! :)