Things to Read
At 15, I read Rich Dad, Poor Dad. It inspired my interest in finance, but there is many errors in the book and I would not recommend it. It also gave me a very wrong idea that investing is a sure thing.
Here are the books I would recommend in respective order:
1) Four Pillars of Investing
2) Ivy Portfolio
3) Random Walk Down Wall Street
I think Stocks for the Long Run is a good reference book, but not the first book I will read.
While waiting for Four Pillars of Investing to arrive from amazon.ca or chapters.ca, I recommend reading this important study: papers.ssrn.com/sol3/papers.cfm?abstract_id=962461 It's free of charge and about 50 pages to print.