What you need to do is:
1. Determine what you need (size, # of rooms, Garage, detatched or semi, etc)
2. determine price range (get pre-approved for a mortgage, also find out what your current place is worth)
3. determine area (consider distance from work, if the area fits your lifestyle, if it's close to things you want). Do an initial search on
www.mls.ca for places that fit criteria 1 & 2, mapquest the addresses, and drive around those areas and start eliminating. Once you have your list down, call up your agent and have thorough look at the inside and outside of the leading contenders.
Also, you may want to sell your existing place first. I know of 4 people who had trouble selling their existing place after buy a place. In one of the cases, he had to resort to renting his old place. Luckily he had enough equity built up to pull that off. Because of that, when I moved last year, I chose to sell first. The worst that could have happened then is that I can't find a suitable place so I would just have to temporarily store my stuff and live in an apartment for a month or two.
Once you've picked a place, put in a conditional offer... the condition being the home inspection.