I've been living simply for several years now as a means to retire early. Back in 2004 I was heavily in debt after a nasty divorce and saddled with huge child maintenance payments, but I made the decision to retire to Thailand in 2012. It looks like I will be hitting that objective this year, and I've already taken several mini-retirements along the way.
Just to reiterate what one commenter posted earlier - you don't need to know a lot, just write down everything you spend, and start assessing where your money is going, then cut back. To be honest it's not that hard. There are those out there (some quite well known) that don't advocate this approach of tracking expenses, but I found it worked very well for me. I found living simply to be, err, simple.
This year I'm becoming much more minimalist, which is a natural progression in many respects from voluntary simplicity.
There are two main resources I used, and found very useful, and both of them have already been mentioned, but I'll list them again:
1) Walden by Henry David Thoreau
This was recommended to me by a friend living a frugal (but rich and happy) lifestyle in Bangkok. It really provided a lot of inspiration, and consolidated various suspicions I'd had about life, the universe and everything. I love this book, and listed it as one of the 5 books that changed my life on my website (see below for link to review).
2) Your Money or Your Life by Joe Dominguez and Vicki Robbin
I can't heap enough praise on this book. Although I'd already made a number of positive changes by the time I'd stumbled across this book, it certainly help me move towards financial freedom a lot faster. This book provides a lot of useful practical advice.
In summary, I wouldn't fret too much. Just dive in. When I started simplifying my life I knew nothing, but you soon get the hang of it - it's not that hard.
Good luck! (Actually it's been a while since you posted - just wondering how you are getting on?)
5 Books That Changed My Life - Regards From The Balcony