I currently live on the West End, but go to school down town and work on Whyte Ave (Driving rules

).
Anyways...
There is nothing wrong with living north of the river, if anything the LRT has about three different stops and the Transit is going to run far more frequently. Rent in some buildings can still be pretty reasonable given the fact that a fair amount of the middle working class down town do not drive. Your barrier for downtown should be that you should NOT live north of 104ave. The 104 ave area is a very nice white collar area, but just 2 blocks north is full of jamaican gangs and homeless people. Also, I would probably stay away from areas east of 90 ST and west of 124 ST (as it becomes a checker board of sketch properties, as far as downtown goes).
University area is nice, but keep in mind that it is full of apartments that are over priced for two reasons: They are either nice quality and in a phenominal location, or crappy quality and in a phenominal location. I have a friend that pays $1100/m for a one bedroom on 81ave, but it also still has red shag carpet that is older than me. So you will really have to hunt if you chose to live in this area, but keep in mind you will be competing against 40,000 other students, as well as landlords that understand the value of their property.
With the expansion of the LRT south, you can now look at living in the Southgate Area or prehaps even Century Park (right, Yeah Baby?

). They are both nice areas with more options and rent hasn't increased as rapidly since the LRT is still a recently development in that area.
Hope this helps. Feel free to PM me, as well, if you have any questions.