There are lots of ways to use the Internet as part of a job search. But as much of a leg up it can give you, there is a flip side to the Internet that also affects your job search – social networking sites. While most professionals regard LinkedIn as part of their professional life, many of them assume that things they have entered on other such websites are part of their personal life. Not so! Employers are as likely to look at your Facebook postings as they are to look at your resume. Once something is posted on the Internet it is public information available to anyone who is online and interested.

Probably the most valuable site for professionals, LinkedIn, can also be misused. Make sure your postings there have correct grammar and spelling and that your thoughts and responses are coherent. Prospective employers may see your profile as a sample of your writing. Don’t forget to proofread! Be sure to get several referrals on your LinkedIn Profile. These will be read and definitely make a difference.

Twitter is one of the most easily misused of these sites. With only 140 characters available for each message (known as tweets) many people are using it as a place to vent anger, joy, and random thoughts — frequently not completely thought of from a professional viewpoint. Would you want to have a potential employer read a tweet that you sent saying telling everyone that you can’t stand your boss or that you’re goofing off at work? Probably not a good idea.

Other social networking sites include MySpace, Plaxo, Squidoo, Ning, Eons and Meetup. There are a total of 153 social networking sites, according to Wikipedia, ranging from those of general interest to Geni.com (families, geneaology), researchGate (for scientific researchers), and Vampirefreaks (gothic and industrial subculture).

Follow me on Twitter and LinkedIn.