LinkedIn is a lot like a very detailed job board. Headhunters search it, looking for people with the right experience; colleagues can expand their networks and round out their contact lists with people in other fields. The most basic level is free to join, and offers everything you need to begin networking effectively. Here are 10 ways to use LinkedIn (for more tips, be sure to check out Guy Kawasaki's excellent post on the subject).
1.) Use LinkedIn for professional networking only. No cutesy quotes or status updates here, and make sure you use an email address that sounds professional. Think of it this way: LinkedIn is to Facebook as your business card is to your a scrap of paper with your name and phone number scrawled on it. Don't post anything you wouldn't want to be asked about -- or held against you -- in an interview.
2.) Input all of your resume information. It's not like a paper resume, where you're encouraged to keep the information to a single page. Take the opportunity to detail as much as you can, and go as far back into the past as is relevant -- you're not limited to your most-current experiences. Keep the language professional, but feel free to add your awards, accolades, and additional skills -- this is your chance to shine.
3.) Add to your contacts. As you increase the number of people to whom you are connected, you also increase your visibility on the site, showing up at the top of search results and in the email notifications that go out to people in your network.
4.) Ask for recommendations. Recommendations are like those references you're supposed to provide upon request -- except that they've visible for all to see, all the time. You can customize your request, if you like, but the site also has a handy, automatic email that you can send out, which eliminates any awkwardness.
5.) If you have another professional blog, link to it. Think of it as a chance to show off your online portfolio. If you don't have a professional blog, link to examples of your work instead. Linking to your current company's website is fine, especially if it showcases some of your accomplishments. Linking to your family's online photo album is not.
6.) Direct people to your LinkedIn profile. Don't just use the default URL that came with your profile -- change it to something easily recognisable, like your name, and use it along with your signature at the bottom of emails.
7.) Take the time to look over your contacts' contacts. It becomes like Six Degrees of Separation -- If A is networked with B, and B is networked with C through G, then A also has access to information from C through G. Your access to each contact person is better if you ask them to network with you directly, though (you wouldn't want to send personal emails to people with whom you are not directly networked).