I just started recently, so I can't give much advice. I first read Learn to Earn (absolute basics), and then One Up on Wall Street (value investing philosophy and basics), and just started Beating the Street (I heard that it's about the practical application), which is the last book in the series authored by Peter Lynch.
I don't even have the very basics down yet, so trying to cover those first. I was supposed to start studying this at 13, but it was too overwhelming for me. I regret not learning this back then, and I'm almost 20 now. It's better if you start sooner, as it gives your money more time to work for you. You don't have to gamble with real money at first, there are several websites/apps which let you do virtual trading.
Looking forward to /u/wheeliedave's reply on this.