So, you want to get in on the action. Wall Street used to be a place where only the rich got richer. That's changed. Whether you're looking for a way to pay for college, buy a new car, or even save for retirement, investing can help you to achieve your goals. But, before you get started, there are some things you should know.

How much money will you need? Many on-line brokers and mutual funds require a minimum investment of $500, $1,000, or even $2,500. There are a few, though, that will allow you to start with no minimum amount.

There are other approaches that don't require as much cash up-front. Some stocks and mutual funds offer automatic investment plans where you agree to invest a set amount each month. In that case, you can often start with as little as $50 or $100. Some companies also offer Dividend Reinvestment Plans (DRIPs). Enroll in the company's DRIP by purchasing as little as one share of stock and you will have the option of purchasing additional shares of stock for little or no transaction fee.

The downside to both of these types of plans is that the company usually sets periodic buy and sell dates - and you have to wait for those dates to make transactions.

If you want to buy and sell on the days of your choosing, you have two options: a traditional (full-service) or an online broker. Traditional brokers usually work out of local branches (think Smith Barney and Edward Jones). Some credit unions also offer these services. Because they offer advice in addition to processing your trade, full- service brokers often charge higher commissions - in the ballpark of $35 per trade.

Online brokers conduct the transaction only. They offer research but, unlike traditional brokers, don't offer advice. The benefit: they charge a lot less - usually between $7-15 per trade.

It's important to keep tabs on the commission fees you're paying. If you start with $100 and are paying $7 in commission to buy and sell, you'll end up only being able to buy $86 in stock.

Okay, let's assume you have the money and a broker. You're ready to swing for the fences. How do you pick that perfect stock? There are hundreds, if not thousands, of ways to pick a stock. The best start is to invest in what you know.

That new enzyme biotech company might seem like a "hot" pick, but if you don't understand the industry, what basis do you make a decision on? Look to companies that you understand and see in your everyday life. Maybe you notice that a certain clothing retailer is doing well and your friends are all wearing their line, or your favorite computer company has a new, successful product. These would be good starting points for investments rather than a company you don't understand.

There are a number of different order formats you can use. A market order allows you to buy a stock at the market price. If you place a trade to buy ten shares of XYZ stock, trading at $30 per share, that's likely the price you will pay. However, if you place an order after the market closes, you will get the price that it opens at the next morning. If the company releases important news after the market closes that makes the stock jump, you could end up paying a considerably higher price.

That's where a limit order comes in. Unlike a market order, a limit order generally allows you to decide at what price you want to buy a stock. If XYZ stock is trading at $30 per share and you want to pay $28 per share, you would place a limit buy order. This tells the broker to buy the stock "at or below" $28 per share. Some brokers charge an extra fee for this - usually around an additional $5 per trade.

Most people think that picking the right stock is the hardest part. Often, knowing when to sell is equally challenging.

I use a method I call "checking the meat" (no offense to the vegetarian readers). I set a specific date (usually every few weeks or months) on which I will reevaluate my stocks and determine whether or not I consider them to still be good investments. Would I be willing to buy more of this stock? If the answer is "no", then I sell. If I still consider the stock a good investment at that price, I hold.

Another method I use includes stop loss orders. I absolutely hate losing money in stocks, and I occasionally pick the wrong one. To prevent myself from picking a real dog, I place a stop loss order right after I purchase a stock. A stop loss order is an order to sell the stock if the price drops to a certain level. If I bought XYZ stock at $30 per share and was worried it would fall, I would place a stop loss order at $26 per share. If the stock fell to $26 per share, my shares would immediately be sold. (There are some exceptions to this that I won't delve into in this article.)

Whether your goal is to become a multi-millionaire (or, ehem, billionaire) or just live comfortably, investing will definitely open doors for you. Just remember to be patient and enjoy the ride.