Amazon Road Bikes
Amazon is one of the most trusted sites on the internet, as well as books it sells a wide variety of products including road bikes. Check out a selection here:
http://astore.amazon.com/cheap.road.bikes.amazon-20
Road Bike Review
A comprehensive review site covering all aspects of road bikes.
http://www.roadbikereview.com/
Bicycling Magazine
An interesting site covering news and reviews on bicycling.
http://www.bicycling.com/