When you set out to buy a car, the first thing you want to do is research. Determine what kind of car you want, starting from whether you want a car, a minivan, or an SUV. Do you want a hybrid or electric car? A hybrid car has an electric motor as well as a gas motor, which definitely makes them more fuel efficient than a regular gas car. An electric car runs off a fuel cell- there are many new buses that run off fuel cells.
In choosing a car, you want to think about reliability, prestige, cargo space, and perhaps color. It really depends on what is important to you and what you need.
When you go to the dealership keep in mind the kind of car you want. A dealer might try to steer you towards a more expensive version of the car, or even a different car altogether if you are not specific about what you want. Dealers do not always have your best interests in mind, but they do want you to be happy, so if you stay firm, you will get what you want.
You may want to consider whether you want to lease or buy a car, a decision which really depends on how often you buy a new car. A used car may also be the best choice for you, especially considering how quickly cars depreciate. A car that has been leased for 6 months can be worth considerably less than the same model year car that has been sitting on the lot. A two year old car can be much less expensive, while still being under warranty, as well as having many of the kinks worked out and any recalls having been done.