From Market Club
Crucial but often overlooked, money management practices can mean the difference between winning and losing in the markets.
Plenty of books, manuals, and software packages will help you form and opinion of a market, but not many will tell you how to trade once you have decided to get long or short. The goal of money management is to increase the odds of high quality trades. And as we’ll see, leaving the money management variable out of your trading equation can lead to ruin, even if you’re correct about the market direction.

In a broad sense, money management can encompass those elements of trading outside the initial decision to get long or short in a given market or markets – that is, how many positions to put on, when to get out, where to place protective stops. More specifically, it refers to the strategic allocation of capital to limit risk and optimize trading performance in the long run. Allocation of capital can refer to how much money to put into any one market or how much money to risk on any one trade. These decision directly affect how many positions to put on and where to place stop orders.
Given the negative odds inherent in trading (a successful trader can expect to lose money on 60% of his trades), how do you go about maximizing the profit potential of the few winning trades you can expect to have? The answers vary with the disposition and trading style of the individual trader. There exist, however, basic concepts that can be successfully adapted and modified to individual needs, and when the followed in spirit, can boost the promise of long-term trading profits and take some of the stress and uncertainty out of trading.
-Establish A Goal- Having a clear idea of what you want to accomplish by trading, whether it is a short-term profit on a single trade or the desire for a long-term trading career, can go a long way toward building successful trading habits. Regardless of whether or not the goals are set on a per trade, daily or long-term basis, establishing from the outset basic levels of acceptable risk and financial reward will help curtail avoidable risk and extreme losses. Also, determine a specific time frame in which to trade: Will a position have to be liquidated by a certain time for tax purposes or for same other reason?
A good rule of thumb is to stick with what you are comfortable; do not venture blindly into unknown markets just for the sake of diversification. A balance must be stuck between available resources and a manageable trading scenario. Capital constraints will, of course limit the choices traders can make, forcing those with smaller trading accounts to bypass or minimize diversification.
From Market Club

stop, but always be wary of straying too far from the basic asset allocation parameters established earlier. For example, if a trader is long one S&P 500 future at 450.00, a based on his total equity he has a $2,500 to risk on the position, he might place a sell stop at 445.00, which would take him out of the market with a $2,500 loss ($500 per full index point, per contract). Buss after consulting his charts, he discovers strong support at the 444.55, a level he believes if broken will trigger a major break. If this level is not broken, the trader believes, that rally will continue. So he might consider putting a stop at 444.55 to avoid being stopped out prematurely. Although he’s risking an extra $225, he’s staying close to his money allocation percentages and modifying his system to take advantage of additional market information.
