hi,
If you check this website www.gumtree.com you can find a lot of rooms which are on offer for students. Although make sure not to transfer any money before you check the property
Winton ,Charminster and Wallisdown road are some of the areas where you can find many rooms and are quite near to the university. hth
http://www.gumtree.com/double-room-flatshare/bournemouth