Managing your own financial portfolio has never been than with the Internet. Via the Web, you can get instant access to the important information you need to make timely buy and sell decisions.

The single best source for online financial management information is Yahoo! Finance.

You may think, "How does Yahoo! know so much about stocks, bonds and other finance issues?" The answer is that Yahoo! doesn't, but they do know how to leverage their position as the premiere provider of Internet content and get impressive companies such as Reuters, Standards & Poors, Associated Press, The Motley Fool, Zacks, and EDGAR Online to offer their information free.

The most important thing to know about Yahoo! Finance is that it designed to be customized to your interests instead of just viewed in its initial generic state.

Before getting too deep into the site, sign-in. If you don't already have a free Yahoo! account, you can create one in less than a minute. With this account, you can also enjoy other free features like Yahoo!'s e-mail, multi-player, interactive games, personalized news ticker, online pager and more.

After signing on, click "Create New Portfolio" in the "Portfolios" section. It is the portfolio section that makes this site so valuable.

Enter the ticker symbols for each stock, mutual fund, corporate bond or market index you wish to track. Don't worry if you don't know it off the top of your head, Yahoo! Finance has made it easy to look it up.

You can enter the amount of shares owned, purchase price per share and date of transactions. Yahoo! Finance can also automatically subtract commissions off returns, set upper and lower limit reminders and let you add notes for each tracked item.

The type of information available for each symbol depends on whether it is a stock, bond, mutual fund or market index. For stocks, you get the open and previous close, bid, ask P/E, dividends, gains and much more. All the information is continually updated 24-hours a day, but are quotes are delayed 15 minutes for NASDAQ and 20 minutes for all the rest.

You can select a variety of ways to view your portfolio information including Basic, DayWatch, Performance, Fundamentals, Detailed or even create your own customized view.

For each stock you also get performance charts displayed by days, months or years. You can easily see your progress at a glance with these charts.

Yahoo! Finance has links to the latest, up-to-the-minute news, special research information, every related company SEC filing imaginable and the details of insider trades.

In addition to specific information about each stock, corporate bond, mutual fund and market index, you also have access to a wide variety of more generalized finance information.

You can check the latest in U.S. initial public offerings or international news, chat online with other investors, read the advice from The Motley Fool or TheStreet.Com or scrutinize the upgrades and downgrades from the big firms.

If you are up to it, try your skills at The Investment Challenge "fantasy" stock trade game where you get $100,000 in your fantasy portfolio to do with what you please. If you come out on top after one month, you can win a new car.

While there are a few sites online that can beat Yahoo! Finance in specific informational or stock charting areas, no one beats them in shear ease-of-use and the wide variety of free information the give the investor. This is definitely worth any investors time.