Before you begin learning all there is to know about money management (MM).  I think you should be clear about it's purpose in trading so you comprehend how important it is to your survival as a trader.

Put simply, without proper management, you will not survive, PERIOD.

Your goal as a trader is to position yourself in a way so that you can survive long enough to learn how to trade.  Most are in such a rush for quick profits that they position themselves in a way that mathematically guarantees their failure. 

It does not matter how good your trading system is, if you are right 80% of the time and do not have proper money management you are setting yourself up for failure.  The lack of it's understanding accounts for a good share of the losers, big and small, that wash out of the markets every year.

The next time you get a chance, take a second to look at some of the outrageous ads some of these guys put in your face and you will always notice three things:

1. They promise you that they have a system that can pinpoint tops and bottoms and predict the future.
2. They usually spend 0% of the time educating you about any aspect of money management, because the average trader does not care to learn about it, the average trader only wants to know about entry strategies.  That is why the average trader fails.
3. You can learn about how most of their system works just by reading the descriptions. 

There is no strategy that can predict the future, most educated people rationally understand that the future cannot be predicted, yet they some how think if they pay a large sum of money, they can avoid that reality.

That is not to say that these vendors are selling a bad product, just to say that they are only selling you less than half of what you need to be successful with their product.  There is nothing wrong with buying a trading system, they can save you time vs. developing one on your own.  Just understand that the trading system only contributes about 10% to a consistently profitable trader.  You may not believe that statement quite yet, but keep reading, and you will.

THE GOOD NEWS:

The good news is you don't need to pinpoint tops and bottoms or predict the future in order to make money trading!  Instead with the proper money management and even a mediocre trading system you will start to make money by waiting for the future, instead of predicting it.  Now that sounds a bit more realistic doesn't it?

To Fully Understand this Key Concept read Trading for a Living: Psychology, Trading Tactics, Money Management