When you are new to exercise, learning as much about training for beginners as possible will be very beneficial for you. When doing research about training for beginners, be sure to look at all the aspects involved with fitness such as cardiovascular work, weight training programs and flexibility exercises. You will want to include all of these components in your routine so you get a well-balanced fitness program. They will also help you to develop a strong fitness base that you can then transfer over to more advanced workout styles.
Another important point is finding a personal trainer that is knowledgeable with training for beginners. If you start working with someone who does not understand the level that you are at you are likely to wind up injured and this will most definitely cut your fitness career short. Nothing is more discouraging for someone who is new to working out than being injured. Not only will you then need to take time off but you may also develop a strong fear about trying that activity again. Instead you want to make exercise feel safe for yourself so that you are comfortable doing it on a daily basis.
Finally, when just starting out always remember that since this is a whole new experience for your body you must start slowly into it. Do not become a victim of the 'too much too soon' trap as many individuals do. It is better to progress slightly slower in the beginning than pushing yourself to hard and creating more muscle soreness than is needed. Always remember that you are likely not to be sore the day of the workout but the day after. Therefore, while your body may feel fine while you are performing the exercise, it is the next day you will pay. This is why it is always better to error on the cautious side.
As long as you are smart with your workouts, there is no reason why you cannot enjoy them injury free and see a significant amount of improvement over time.