There is a famous New Yorker magazine cartoon of two dogs at a computer with the caption, "On the Internet, nobody knows you're a dog." This funny warning sums up the truth of the Web-anyone, anywhere can put a Web page offering information and advice. If you are using information found on the Web to make decisions-about your health, your investments, your vacation, your pets, or any other part of your life-you want to be sure the information is accurate and reliable.

It really is up to you to determine the validity of the information on any Web site. But among those billions of Web pages, how do you know which ones to trust? Where to begin? Ask yourself some questions about the site, be skeptical, trust your instincts, and find more than one source whenever possible.

Here are some things to look for on a Web site:

• Who put up the page? Do they explain their credentials or affiliation? Are they trying to sell something?
• How recently was the page updated?
• Are there links to other Web pages? Do these pages seem valid?
• Does the information seem credible?

LifeHacker, a blog that offers tips on computer use, and University of California, Berkeley Library have excellent pages on evaluating Web sites. Each has additional links for more information.

So, surf away to find a great place to surf on your vacation, but be aware that there are misleading and inaccurate sites out there! Surf smart and evaluate any information from a Web site before you use it.

One way to know that the Web sites you are viewing are reliable and contain authentic information is to use a trusted Internet directory. A Web directory is a collection of Web sites that experts have evaluated for accuracy. Directories are organized by broad subject headings with more specific topics under these headings.

Here are three directories compiled by librarians-and we know librarians are information experts!

Librarians' Internet Index A collection of tens of thousands of entries organized into 14 main topics and nearly 300 related topics. A great first stop on the information highway.

Internet Public A collection of subject directories, links to reference sources like almanacs & dictionaries, special sections for kids & teens, reading resources, & more. Just like a "real" library!

Digital Librarian A New York librarian maintains this list of thousands of links organized under 100 headings.

SELCO, our regional library system, has a directory, as do many other libraries and library organizations. There are specialized directories, too, such as this genealogy directory. Use Web directories as a shortcut to find reliable Web sites.

It may seem that as soon as you have an email box, it is filled with messages that alert you to potential crimes, warn about your health or your pet's health, denounce bad corporations, tell stories of sick or missing children, and offer free ice cream or other stuff. And while some of the information is true, most is unreliable and aimed at the gullible.

Email, with its instantaneous delivery and worldwide reach, makes spreading urban legends, chain letters, and other junk emails a one-click operation. You can check out the truth of these stories and offers at these Web sites. Test your Web hoax savvy with this quiz.

These forwarded messages can be worse than spam and harder to stop. After all, most come from your trusted sources-your family and friends. Think twice before you forward jokes, warnings, and stories to all your address book contacts. Most people hate junk mail cluttering their inboxes-no matter how cute, funny, or inspirational.

All of these Mystery Links take you to Web sites that contain credible information for your entertainment and enlightenment. Or do they? Use your information evaluation skills to determine which Web sites are the real deal and which are put up as satire or as hoaxes to teach information literacy.