Want to check up on how stock in Walt Disney Co. has been doing over, say, the last six weeks? No problem, just sign onto any of a dozen free Web sites that provide news and data on the Burbank-based company.

There used to be a time, not so long ago, when investors relied mostly on their brokers for detailed information about a company. But now the Internet has changed all that.

In the past year, sites have been launched that offer everything from tips on hot issues to educational articles to comprehensive databases of available stocks.

“We’re seeing a steadily growing number of people hitting our site,” said Bryan Christian, a spokesman for Hoover’s Stockscreener, a stock database site developed by Austin, Texas-based Hoover Inc. “I believe that we and yes, some of our competitors are going to continue to see an increase in users.”

The sites fall into two categories: those that offer advice and those that offer database searches. Some publications and advisors provide this information for a fee generally $10 to $30 a month but there are over a dozen free sites.

Online users have seen the informational and advisory sites proliferate, with everything from established magazines like Money Online to tip sheets that only appear online, like Market Rap, establishing a presence.

One of the better-known advice and educational sites is Motley Fool, which has a variety of stock market news, educational workshops and profiles of success stories and failures.

While most of these information sources are reputable, industry experts warn that there are a few drawbacks. First, Web sites should be used as a jumping-off point in the investment process.

“These screens are good as an educational and informational tool to use as a part of the learning curve,” said Esther Berger, senior partner of Beverly Hills-based Berger, Jaffe & Associates LLC. “However, these things are most useful at the beginning of the investment process not the end.”

Also, like all information on the Web, it’s crucial to consider the source. A recent search of stock advice sheets on the Web turned up not only established sources, such as the Wall Street Journal’s online edition, but recommendations from college students on what they believe to be hot stocks.

“Investors should be very concerned about the advice they receive from any source, whether online or not,” Lawrence Harris, a professor of finance at USC’s Marshall School of Business.

Another drawback with tip sheets is that they may prompt gut-reaction trades.

“Investors get more emotionally involved and run the risk of short-term behavior that will not profit them,” Berger said. “It’s so easy to get caught up in hot tips that investors may not think through their actions.”

The other category of online stock market tools, stock databases, do not give advice but do help generate ideas for stock investments.

The sites which include Hoover’s Stockscreener and Standard & Poor’s Stockinfo allow users to establish a variety of parameters about the type of stock they want to look at. Each site offers a different set of parameters, but all include basic items such as price/earnings ratio, dividend yield, market capitalization and past stock performance. Some search engines have variables so detailed that a person can request information only about companies that have a certain number of employees.

The program then searches the database to present a list of stocks that match the entered criteria. Most of these sites offer convenient links to an online trader if an investor decides to take immediate action.

Of course, the adage of “garbage in, garbage out” can apply with these sites.

“These pages are a great research tool,” Harris said. “But with systems like that, the usefulness of the answer depends on how good the question is.”

The companies behind the stock search engines are aware of their programs’ limitations.

“Stockscreener is really just a search engine, and one of the assumptions is that if the user is able to fill in the criteria on the Stockscreener, they are aware of the risk in the market,” said Hoover’s Christian. “We do not think of our site as a recommendational tool it is designed to be for research only.”

Some of these database sites are hybrids, offering educational and advisory elements as well as pure statistics. Marketguide has a “what’s hot, what’s not” section, Morningstar offers lessons on the stock market under the title “Investing 101,” and Stock Tools has a short list of its stock picks.

“All of these sites are just great information resources for the individual investor,” Kruger said. “My clients love them. Users just should be aware of their limitations as well as their power.”