Find a successful local bike shop with a good inventory and excellent service. Find out if they are helpful or bike snobs.

If they fit the bill, purchase from them.

Having a local support system (LBS) is amazing. I don't think you can get better than mine (Peachtree City Bike Center). These guys are all serious riders, and yet they take the local commuter seriously, even though my needs are so much different than theirs.

I can ride my bike up anytime, and they throw it on the rack, adjust it, lube it, check it, and I'm on my way. No charge, no questions asked. Done.

I'll stick with them. They happen to be a Trek and Redline dealer. I'll stick with them.