provides FREE online educational material to help you learn the accounting concepts practiced in the United States. The site provides hundreds of pages of explanations, drills, exams, crossword puzzles, and a glossary of over 1,000 terms.  
The World's Largest Free Online Accounting Course
Accounting is actually quite useful
SpearmintFur: If you wanna get into investing, it explains A LOT without the hype of those "get rich quick" books.  
I recommend learning accounting.