You want to get fit, and make a resolution. Starting to exercise is not always the easiest decision. So whatever your reasons for starting to exercise and however you plan to do it, make sure you are doing it for the right reaons as this will help to motivate you to get fit.
When you are starting to exercise, it's important that you have reasonable expectations. Too often people jump in with both feet, a gung-ho attitude, and a recipe for failure. The result? With a few weeks (or sometimes even days), the commitment is gone, the resolution broken, the new gym membership wasted.
If you are starting to exercise after a long lay-off, if you have any health problems, or if you're pregnant or elderly, then the first port of call should be your doctor's office. Get a check-up first in order to be clear what you can and can't do.
Next, you need to plan what you are going to do and when - it's better to begin with a conservative, flexible plan, rather than a rigid one that you won't be able to stick to. For example, rather than saying "I'll go to the gym every day this week", begin with "I'll go to the gym three times this week." You increase your chances of success, and will have the reinforcement of having met your goal to motivate you the next week.
Similarly, you need to go slowly to begin with. If you've been inactive for years, you can't run the London Marathon after two weeks of training. Don't try and outdo the people you see at the gym who have been working out for years. Allow yourself the time and space to warm-up slowly, take your workouts at an easy pace, and let your body adapt to the new strains you're putting it through.
If you begin carefully, you'll soon be able to build up the frequency, time, and intensity of your workouts, and more importantly, you'll be much more likely to stick at it in the long run.