A) When I first learned about LDing it took me all of two days to have my first Lucid Dream… That being said, it took me about two or three years to get to a point where I was trying to have lucid dreams on a regular basis. During that time I had them occasionally, but not very often.
B) Like Mew151 said, to have fun! The real reason, though, is that since the average person sleeps for 8 hours a day (a third of his or her life!) I wanted to reclaim that time be it used for relaxing, exploring, fighting, swimming, climbing, gaming…
C) At first, I didn’t use any method. 
My excitement forced my first LDs upon me in a few days. They were short LDs, but they were LDs. After that the most consistent promoter of LDs was recording my dreams, keeping a DJ. When I had slumps and stopped writing in my DJ my LD count went down. In fact, what caused my LD count to jump in a few months (a few RECENT months) was keeping my DJ on a regular basis and participating in things like the Lucidity Challenge.
D) I had 7 LDs this January (2014). I don’t have any long-term projections over the course of my entire LDing history because I’ve been lazy and haven’t done the statistics yet.
E) I’d say the most important thing that happened to me in a dream was an unusual (F)LD thing that happened to me in July 2012. (The Orb Figments - Continued. You’ll have to scroll down through the post. It was a bulk update. ) It inspired me to be diligent in keeping my DJ and is the reason why I’m at the level I am now (which isn’t all that high, but definitely higher than I was a year ago 
).