How to buy a bicycle
What type of biking do you plan on doing?
There are several different types of bikes for different types of riding. If you're going to be using your bike as transportation for a 5+ miles a day, you'll probably want to get a road bike. If you're going to be doing a lot of off-road riding, you'll want a mountain bike. If you're more into stunts like wheelies and don't plan on riding long distances, then a BMX bike is right for you. Hybrid bikes are also very popular, as they mix some of elements of a road bike like thinner tires with the ruggedness of a mountain bike.
Although I love road bikes, you should consider the condition of the roads in your area before buying one. They can get quite expensive and you don't want to spend money on a bicycle that you'll be uncomfortable riding in your area because the roads aren't smooth enough. Road bike tires and wheels lack the ruggedness found on mountain bike wheels, so they can't take too many jumps or potholes before becoming damaged.
If you plan on riding your bike long distances on paved roads, the road bike is just what you're looking for. Road bikes are fast and because the tires are thin it creates less friction with the road surface, making it easier to ride without wearing you down.
If you're planning on touring over hundreds or even thousands of miles with your road bike and carrying extra cargo you'll want to look into buying a touring road bike. Some models that are particularly good are the Trek 520 and the Surly Long Haul Trucker. You'll want to make sure your bike comes with a rack and also buy panniers (which are basically like saddle bags) to attach to the rack.
The hybrid bike looks like a mountain bike but with thinner tires. It has the same flat handlebars that are popular on mountain bikes and differ from the drop handlebars seen on road bikes. This also allows the rider to have a more upright posture on the hybrid bike, which is more comfortable to some but also means slower speeds due to poorer aerodynamics.
Some of the top model hybrid bikes include the Specialized Sirrus Comp, the Jamis Coda Elite, an the Trek Valencia.
There was a time in the 1990's when everyone was riding mountain bikes. Road bikes had fallen out of favor and even people who were riding 20 miles a day were choosing the more rugged and slower mountain bikes. This seemed foolish, as mountain bikes are really made to be ridden offroad on unpaved surfaces. I think the bicycling community has come to their senses now as more people are using mountain bikes for the special purpose and not for everyday commuting.
Some top model mountain bikes include the Trek Fuel EX 8, the Kona Cadabra, and the Specialized Hard Rock Sport for those on a budget.
To be honest, I don't know too much about BMX bikes. When I was young we didn't really have them, as the BMX phenomenon hit at the same time skateboarding became really popular again in the mid-1990's. The skateboarders and BMXers seemed to mix well together as they competed in the X-Games and worked together to build skate parks that both could enjoy.
Popular BMX bicycles include the Mongoose Shield BMX Freestyle, the Kink Curb, and the Eastern Bikes Shock.