LinkedIn has been called "the Facebook of the professional world," and that's only partially true. For example, LinkedIn goes far beyond social media, allowing people to advertise or directly apply for jobs right on the site. Unfortunately, because it is technically social media, LinkedIn tends to lure people into a sense of calm complacency, allowing them to forget that they have to maintain professional etiquette standards just the same as if they were going into a building for an interview.
1. Be Upfront
LinkedIn users who are considering prospective employees want to look at your resume. As with most people, they're bound to find a few gaps in employment. Presumably you'd fill in these gaps with information on a traditional resume (for example, if you took time off to write a book, have a kid, or go back to school), so do the same on your LinkedIn profile. While it shouldn't need to be said, don't lie on your LinkedIn profile any more than you would on a real resume.
2. Keep your activity hidden, but your profile public
Obviously, more recruiters and hiring managers can see you if you're public, but you also don't want your prospective employer to check you out on LinkedIn and see that you've been chatting up other prospects as well. Keep it as polished and clean as possible, and don't clutter up your page with endless streams of activities. New employers are interested in your resume, not your online news feed.
3. Be friendly, but not overbearing
We tend to forget traditional etiquette when we're hidden safely behind a computer. So when speaking to a recruiter or hiring manager, it's important to be polite and assertive, but not harassing or bullying. You're not anonymous on LinkedIn, and people will remember how you treat them. If you wouldn't say a certain thing within their four walls, don't say it on LinkedIn.
4. Log in
If you haven't logged in or updated your profile since you started your account four years ago (before graduation, your first job, and your first promotion), anyone looking at your profile is going to be concerned that you're not interested in furthering your career, or worse, that you haven't done anything since college. Give it a quick refresh every now and then to show that you care about where your career is going.
5. Don't pester people for recommendations
If you worked closely with a colleague or classmate on something, it's fine to ask for a recommendation about your knowledge on a certain subject. If you had a couple of classes with someone ten years ago who doesn't know anything about your work, their recommendation of you might well be meaningless--if they even bother to write one instead of scratching his/her head and wondering how he knows you.
In short, the way you present yourself on LinkedIn should match how you present yourself in an interview. Keep your profile up-to-date, be honest about yourself, and be polite but not aggressive. These tips will help you become a better LinkedIn user overtime and help you grow professionally as well.