"Even if you might make [your social networking page] private, sometimes the friends that you allow access to (Facebook, for example), become ex-friends," says Matt Kerr. He's an executive search consultant in Illinois. "You never know what happens once you put something in cyberspace, or how it can be used or twisted." For instance, an ex-best friend might use photos or posts from your social networking page to make you look bad.

The Internet has a long memory. "Once you have something up there, it's hard to change it," says Kerr.

Kerr warns against flaming -- posting negative things about companies or people. Posting tasteless jokes, negative comments and wild photos can damage your own online image, even if they're just part of a personal blog.

Derek Gagne is president of a corporate services consulting firm. He suggests not posting messages at all when you're angry. "You post a rant about XYZ Company because they're terrible -- for whatever reasons," he says. "That may be true, but it might not be the best place to post it since it may not be seen as the most constructive way to resolve the issue."

"A lot of employers do a Facebook search before even deciding to call somebody up for an interview," Gagne says. "It's almost like a first screening interview." What they discover on your social networking page may very well affect how that person views you. So, try to keep it positive."

Nicole Wyatt is a recruiting manager for Disney ABC Television Group. She says a colleague once told her about a quick online check that showed a job candidate for a major financial institution had a blog about the evils of capitalism. "How would this particular applicant, if hired, prove to make the best decisions for the company if he was so passionate about anti-capitalism?" Wyatt asks.

"Checking websites is not company policy of Disney ABC Television Group, but it is becoming more popular with certain employers," Wyatt says. "What an employer would look for truly depends on what type of position the job seeker is applying to."

Kerr says some larger firms are starting to hire people to check applicants' references and backgrounds. "It's becoming more prevalent," he says. "They'll check all sorts of things, and that could include social networking sites."

Even if companies don't search social networking websites, prospective employers can still learn a lot about job candidates by running their names or e-mail addresses through search engines like Google or Yahoo.

It's helpful to use different e-mail addresses for fun and work. That way, silly things you posted under an address like GirlyGirl@whatever.com won't be found in a search by prospective employers. For work and school, it's important to make sure your e-mail address sounds professional.

"I know of [human resources] people who will just delete e-mail that comes from some strange-sounding e-mail address, (so make sure the address you use is conservative)," Kerr advises.

When creating a business-like e-mail address, Gagne suggests pretending that you're shaking hands with someone and introducing yourself. "What are you going to say to that person?" he asks.

Anyone can get free e-mail addresses through places like Gmail, Yahoo! and Hotmail. Just keep it simple.

"The ideal e-mail address would include your name as it also acts as a quick reference to your information," Wyatt says. If your name isn't available as an e-mail address, she suggests combining your name with your area of interest, like webmasterjoe@whatever.com.

The good news is you can also use social networking sites, blogs and your own website to start building your reputation long before you enter the job market.

"Use them to either highlight or add to the information you might see on a resume," Gagne says. Even if you've never had a job, you can still list your volunteer work and any student groups you belong to. "Highlighting the extracurricular things shows you're getting involved and going above and beyond," he says.

You can also mention any activities, accomplishments or special projects you've been involved in. Don't forget scouting, honorary societies and teams.

"In business, it's all about how well you play in the sandbox with others to get things done," Kerr says. Even if the activities aren't connected to your major, they show you have life skills and initiative.

Posting this kind of information on a personal website, Facebook or MySpace page is a great start. But older students may also consider joining a professional social networking site, such as LinkedIn.

There's another thing people can do with social networking tools, says Kerr. They can research the companies they might like to work for. He suggests ZoomInfo, a free online tool, as a good place to start.

"If you want to find out more about a company, or about the person interviewing you, get on ZoomInfo and check them out," Kerr says. "See if the person you're interviewing with is published. Then get on LinkedIn, because chances are the person interviewing you will have a professional profile [on LinkedIn]." Then, if you find your interviewer has an interest in a particular area, such as education, try to mention it in your interview, he suggests.

Kerr says there's no excuse for not knowing about companies and interviewers, since so much of the information is readily available online. Interviewers appreciate job candidates who take initiative and ask questions.

To improve your odds of landing a great job, Wyatt suggests exploring and creating pages on major social networking sites and web pages. "Build your own professional page and develop relationships on Facebook, Twitter, LinkedIn and MySpace -- to name a few," she says. "Most companies... now allow for job seekers to join as members or fans. Conduct searches on top employers and connect to them in other ways than just applying to specific jobs."

So, start clicking.