Don't work for money; have money work for you

"Money is the seed of money, and the first guinea is sometimes more difficult to acquire than the second million." -- Jean Jacques Rousseau
The first lesson Kiyosaki emphasizes in Rich Dad, Poor Dad is that rich people don't work for money; they have their money work for them. Personally, I'm satisfied when my money earns a 10% return per month for me. If my money isn't providing this kind of return, I start looking elsewhere. For examples of how you too can achieve this kind of return, see Risk Meter.
Fortunately, you don't even need to have money in order to make money work for you. There are millions of people in the world with "surplus" money that's not being put to very good use. You can organize your money-making activities so that some of this OPM (other people's money) works for you. For a general approach to achieve this, see Zero-Risk Money-Making.
See also Make Money Work for You in

Basic Money Skills

There are thousands of self-improvement, success, and money-making books. Many of the authors have attempted to put together some "integrated formulation" from their own experiences and from all the other sources available to them. Unfortunately, most of them -- if not all of them without exception -- are somewhat incomplete and sometimes even hopelessly misguided in some respects. I hope my attempt at formulating some money skills will become more complete than most. If you know or think of any money skills I should add to my list, please e-mail Frederick Mann.
Robert G. Allen (also best-selling author of Nothing Down, Creating Wealth, and Challenge) writes in Multiple Streams of Income: How to Generate a Lifetime of Unlimited Wealth:
"Prosperous people practice seven financial secrets. I call them "secrets" not because very few of us are aware of them, but because very few of us use them. The secrets are, in reality, skills ... essential money skills that all wealthy people practice. I believe that if you learn these skills, wealth can flow into your life ... multiple streams of increasing prosperity. Wouldn't that be nice? Money to buy whatever you want ... houses, cars, travel, freedom. Surplus to share with the people you care most about. Security. Peace of mind. That's what these skills will bring you."
Allen also devotes a chapter to network marketing (or MLM = multilevel marketing), which he calls "the ultimate money machine."