You'll have to set up an account and put in all your educational details and previous work histories. Once you've done this, connect with a few LC key personnel like:
You may also want to link a blog or two to your LinkedIn profile. Your profile page will automatically get a feed from the last 3 posts and anyone interested in what you do will head straight to these blogs.
So far, I've told you how to set up LinkedIn, but not why it's important. You've probably heard the saying: "It's not what you know, it's who you know." This is so true in business. Potential employers are much more likely to hire someone they know or has been vouched for by a trusted source. LinkedIn provides for that, it'll open doors.
Many of the staff that have set up effective LinkedIn accounts have been offered employment by companies outside of LC. Whether you take them up on the offer is up to you, but a good LinkedIn profile will give you these opportunities and advantages that people without LinkedIn don't have.
Furthermore, LinkedIn comes up in search engines. So the more exposure you get online, the better. Make sure you select a good name for your profile, something that fits along the job your doing. Look at the profile page address for Toby or Melanie. These small things count and show proof towards your expertise in the field.
You'll also want to keep track of best answers and topic discussions in LinkedIn. Remember the more accolades you get on your profile, the better it looks. LinkedIn has credibility because any person viewing your profile can see who's said what and in what position they are in. They can validate information for themselves.
Next step: Creating a blog
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Short Stories and other Curiosities