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A good first step is to take some biking classes so you can get your feet wet and see what biking is like and an idea of what they can do with you on one.
Then decide what you are going to use the bike for. Dirt biking, commuting, cross-country riding, etc.?
Keep in mind your ability to work on the bike, where you will store it, and whether or not you will also be able to insure it. I don't know your age, but if you are 18 and get a new racing sport bike, you'll probably spend $300./month for insurance.
Then, decide on your budget. It probably won't be your last bike, so don't be afraid to get a used one that already has dings on it, but is cheaper and easier to unload at a low selling price.
Have your financing lined up before approaching the bike you may want. Remember, no seller wants a buyer that says: "I like your bike, and in several months I will probably have enough money set aside to buy it."
Visit a number of dealers and sit on bikes that fit your parameters. Don't automatically think getting one from a dealer is bad since they are in business and you have somewhere to return it if there's a problem. Plus, you will need a dealer for fixing major problems and getting parts. Later on, you may do your own repairs and get parts on-line.
All bikes have some problems, but most of the major brands are fully functional if taken care of. Don't buy one that looks cool, but you suspect has had someone ride the piss out of it.
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