Excellent guide. I'm happy for any exposure Lucid Dreaming gets as it has deeply impacted me from the moment I accidentally discovered it over 10 years ago.
The more I Lucid dreamed, the more I realized just how powerful and amazing the human brain is, and the consciousness that comes from it. The first things I did was relive certain memories exactly how they played out. I then began making basic changes to my dreams which grew into creating entire worlds. I also have used it to help me understand material in class.
For those of you who have this inevitable "I'm going to wake up soon" problem, where you only have a few minutes before your body forces itself awake...well, you can control that through lucid dreaming as well.
I know this sounds a little nerdy, but it worked for me. I created a heads-up-display that monitored how awake I was. When it was reaching a level where I would be waking up soon, I would force the bar back down to keep me in the dream.
There are no limits to lucid dreaming. It's just an amazing experience.