You really need to Learn 4 basic concepts first.
1. What are all of the financial securities and how they work, (stocks (preferred common), bonds (all of them), mutual funds, UITs, closed end funds, derivatives (warrants, options, futures), hedge funds, private equity, private debt.
2. How does Macro Econimics work. Lading indicators, lagging indicators, PM index, Jobs, dollar valuation, etc etc etc
3. Fundamental Analysis (value, growth, blend, the market caps, etc)
4. Technical Analysis (call it hocus pocus if you want, but if enough people believe in somthing, then guess what)
Once you get all that down, then you can move onto Investment Philosophies and Theories. Markowitz vs Post Modern vs Technically Driven vs Event Driver vs Strict Deviation Management etc etc
Then you can start making some decisions.
Despite Arf.com's attempt to simplify investing as they always do, there is absolutely much more to it than going to Vanguard and buying an Index Fund. Now if that's what you like, more power to you, rock on! Thinking it is the only way to do it properly and effectively is another story.