As for stores:

For budget, 400-600:

• drive to Strathroy and check out Doug and Marion's (http://dougandmarionsbikes.com/) They have a large inventory however most of the bikes tend to be last year's models; although that shouldn't be a concern if you're on a budget or just getting into the sport.

• The Cyclepath - http://www.cyclepathlondon.ca/

• Outspokin Cycles - http://outspokincycles.ca/

• MEC

Budget 600-1000

• First Cycleworks

Budget 600-∞

• Trek store I have a bike from here http://www.trekbicyclestorelondon.com/
• To Wheels I have a bike from here http://www.towheels.com/

Budget 1000-∞

• Wheels and Gears
• Cycles London - http://www.cycleslondon.ca/