First of all, understand that tools are simply that - tools. A chisel in the hand of a novice makes clumsy cuts and produces amateurish results. The same is true of online tools and social media. Learn how to use them effectively to land the job you really want.
Let's focus on the pros and cons of using social media in your job search.
Creating a presence.
Facebook, LinkedIn, blogs and Twitter allow anybody anywhere to create a presence for themselves. These tools offer you a way to get yourself noticed.
Standing out from the crowd.
With thousands of people vying for a few openings it is very important for you to use social media to help you stand out from the competition. Be careful how you do this, of course, but the easiest way to get noticed is to participate in discussions. Make sure you subscribe to or belong to professional associations and affinity groups relative to your academic interests. If educational technology is your thing, then you should belong to and participate in the fascinating discussions on ISEN.
Proving your competence.
You may have a degree from Cambridge University. But if you keep your learning hidden from others, how are they going to know that you are passionate about, and, indeed, an authority on Spanish novellas? Joining in the discussions, tweeting about an article you have seen, or, better yet, which you yourself have written, will go a long way to getting you noticed at least in the circles which really matter. The circles of your peers.
Once again, the social media and online tools are merely a means to an end. The secret to finding a really great job in any profession is having people who can vouch for you and your accomplishments. On every private school job application is a section for professional references. These referees must know you and your work intimately. Building your network is an essential way of accomplishing this.
The biggest negative about anything online is that it is out there for all to see. So be very, very careful about what you say and how you say it online. If you have extremist views at either end of any spectrum, you might want to keep your opinions and commentary to your offline circle. In a similar vein, photos of you at a fraternity party quaffing a stein of beer might seem harmless enough until somebody uses it to sabotage your chances of getting that dream job.
Establishing yourself online requires new ways of looking at how to present yourself and your accomplishments. Get it right and you will have thousands of loyal followers hanging on your every word. Get it wrong and it could be a disaster which will be hard to recover from.
Read what Alison Doyle has to say on the subject. She has lots of useful information and advice on her Job Search and Career Networking page.