Hi Matt:
I went to Waterloo for the last 5 years, and I really enjoyed it there. Just to warn you now, the winters can get pretty damn cold, and in the summer, it can definitely smell like geese poop. So I would definitely recommend getting a place with A/C.
Here are some places to look into for housing in UW:
http://www.waterloostudentresidence.ca/
http://www.wcri.coop/ <-- this place is VERY convenient to campus, but it's pretty dirty
https://listings.och.uwaterloo.ca/Sublet/
There were some new complexes that were being built while I was leaving UW. They looked pretty nice and would be around $500 - $600 CAD per month.
I have a friend who currently has a house right now, so I may get you contact with him, but it is not close to campus.
Hope this helps!