Couple searching for accommodation in Berlin

We are looking for either an apartment or a room in Berlin; ideally in neigbourhoods such as Kreuzberg, Schoneberg, Friedichshain, Mitte or any other in in the nearbies. We are not looking for anything so cozy or luxurious, so it shouldn't exceed the €1000 (if it's less, better). We are a really friendly couple of 20 years both, also very responsible, organized and non-smokers. Both of us speak spanish, english and a bit of german (in process of perfectioning it). We will be studying Global Business in the city for a whole year thanks to an scholarship, if you know of any opportunity please let us know :)