There have been a few recent threads about where to live in Lausanne and surrounding areas that are convenient to the university (St Sulpice, Renens, Ecublens, Malley, Prilly, Crissier). The tourist office used to have accommodation lists with apartments/rooms -
http://www.lausanne.ch/view.asp?docI...358&language=E - however, this may no longer be the case, but you could contact to find out. This was how we arranged our temporary accommodation (2 months). The university should also be able to help you out as they have an office that deals with accommodation.
www.mapsearch.ch may be useful for seeing transport links etc in the neighbourhood.
I opened my bank account when I arrived. It's important to register within the time frame but it shouldn't take long anyway.