How do you know when you have enough money? We all know what it's like not to have enough money, but what is the maximum you would need to fund your life? The real question behind that is how big do you want your life to be?
Money is a game. It has rules and it has strategies. Rules tell you how to play the game: Income, Expenses, Taxes, Investments. Strategies tell you how to win. Here's the strategy you should adopt to be successful at managing your money.
[Concepts from Total Money Makeover by Dave Ramsey, The Intelligent Investor by Benjamin Graham, and The Millionaire Real Estate Investor by Gary Keller. All those books can be found here on the reading list.]