1) Set a Budget
Choose a maximum dollar figure that you can handle and stick to it. Don't forget to include things like taxes and interest. If you're disciplined enough not to stray too high, you'll keep yourself out of financial trouble, and also narrow the field of choices down quite a bit. If you're having trouble finding a balance between cost and features, getting something used is a good option.
2) Decide the Vehicle's Function
This is where you will address your needs, and really start to focus your search. Ask yourself some questions about where, when, how much, and with whom or what will you be driving it. Think about your climate, especially if you get a lot of snow. Do you want something economical or fast? Does it need to meet the demands of your spouse? Don't get too far into making a list of candidates until you've gotten through this step.
3) List Your Desired Options and Features
This is where you will address your wants, items you would like to have, but could live without. You should expect to adjust this list throughout your search, and maybe even sacrifice a few items in order to stay within your budget. You may find that the only vehicle that meets all your needs doesn't offer all of your wants.
4) Do Your Research
This is a very critical step. If you have the time to do it (and I recommend making the time), you could save yourself a lot of frustration later on. Thanks to the world wide web, there are tons of resources for car reviews, ratings, rankings, and test results. Sites like The Car Connection, Edmunds, Kelley Blue Book, and Consumer Reports give you access to professional and consumer reviews. Once you have eliminated all but your best few options, get some insight into the pros and cons of what's left on your list. You may find that this step knocks a few more players out of contention. Ideally, you'll have a handful of options left, at the most, after this step.
5) Get In!
Research will only get you so far. In order to understand how a car will fit you and your lifestyle, you've got to get your butt in the driver's seat. Take it for a spin. At this point, you know your remaining options have meet your needs, wants, and budget. All you need to do now is wait for that good vibe. You may discover that there is something about one of these cars that you just can't stand and couldn't live with. You don't know until you sit down and try it. Be careful not to stray from your original function or purpose. A good salesman might be able to talk you into something you don't need or can't afford.
The order here is important. Each step is designed to eliminate choices that don't meet your needs. If the strategy works for you (and I think it will), you should end up with a fairly short list of options at the end, from which to chose. This will help make the whole process much faster and less intimidating.