What kind of bicycles do they ride in the Tour de France?
The focus is on the riders, because the bikes are just not so different from one another. The UCI (international cyclists' union) tightly regulates what shape and weight the bike must be, and what technical solutions are acceptable, so the sponsoring manufacturers can only compete on relatively minor features such as aerodynamic tubing or frame stiffness. These are of no practical importance to an everyday cyclist.

A typical racing top-level bike nowadays will have 


an aluminum or carbon fiber frame, with increasing focus on aerodynamics over weight (because it's relatively easy to achieve the UCI minimum weight of 6.7kg regardless)
always a carbon fiber fork
either super light or aerodynamic wheels, depending on the type of rider and needs of the particular stage 
either Campagnolo Super Record, Shimano Dura Ace, or SRAM Red component set, depending on who's the sponsor