I really would just sleep as long as you normally would... get the amount of sleep that your body needs, you will dream no matter what.
As for lucid dreams, if regular dreams are experiences that you remember after you wake up, lucid dreams are dreams that you are actually awake in WHILE your body is sleeping. They can seem just as real as real life, and you can learn to control everything about your dream environment, talk to your subconscious, or even learn to have out-of-body experiences from the lucid dream, eventually. It's basically just like realizing that you are dreaming, and "waking up" in the dream without waking up your sleeping body. It's a great feeling. You can even learn to go directly into a lucid dream from being awake without first falling unconscious, although most find this difficult.
If you develop your dream memory by writing your dreams down consistently, chances are you will begin to occasionally have lucid dreams. If you'd like to speed up the process, you can get into the habit of checking to see if you are dreaming by learning certain things about the dream world which differ from real life. So for instance, in dreams many people will notice that they do not have five fingers, that mirrors don't reflect things normally, that clocks don't tell the same time twice, that things don't read the same words twice, that math doesn't work the same, that light switches don't do anything, that turning around or spinning might completely change your environment, etc.
I personally find it easiest to check my hands and make sure that I have exactly five normal fingers. Whenever something seems strange to me during the day, I make sure I have five fingers. Occasionally, I'll check my hand and have many more than five fingers, and know that I am dreaming, and become lucid. You can use whatever method you'd like, and if you do a little research you will find many different techniques for having more lucid dreams.
I am also going to tentatively say making sure you get enough vitamin B6 will likely also help you remember your dreams more vividly... High doses of B6 have been correlated with vivid dreams, so it seems only logical that sufficient B6 plays a role in the ability to remember dreams. Don't take too much, though, just make sure you are getting a healthy amount.