I suggest you go here to find the answers to your questions about lucid dreaming. But it may be more important to understand dreams in general since dreams can be therapeutic. Lucid dreaming can be beneficial to some but in my mind it can take away from the greater experience of dreams. Taking control of your dreams, lucid dreaming, can help in certain aspects to do with dreams but understanding why we dream and the true aspects of dreaming is more important. Once you understand dreams then you will be better able to work with lucid dreaming. To learn more about dreams and dreaming I suggest you go here.