If you are new to mountain biking, the first time you venture out into the mountain bike market can be quite confusing and overwhelming. This is usually due to two reasons, that there are thousands of mountain bikes out there with technical specifications that you probably do not understand and to top it off, a very high price tag.
The good news is that usually you can find much cheaper bikes than you will in magazines, given that the cycles featured are generally, for experts and you will need not that high level of a technical bike yet.
With this in mind, the first thing you need to consider is what your actual needs are when it comes to a mountain bike. For example, do you plan on riding the bike only on trails, or would you like to use it for transportation as well. Also consider how much you plan to use your bike since there are hybrid models that can serve you well as a mountain bike beginner and for road use.
Second, when it comes to a mountain bike you need to think about how much you are willing to spend. Traditionally speaking, the more you spend the higher quality bike you will get, but as a beginner you do not need the top bike at first. Higher priced bikes also tend to be more durable but you also will not be putting your bike through as much stress on a white circle trail versus a black diamond trail, which it will take you some time to tackle.
Finally, the best way to figure out which mountain bike will fit best is to test ride them. Often you can rent bikes near large trailhead, which is an excellent way to trail a bike and find out how you and the bike respond to each other.