— Register your domain name in as many variants as you can find and as early as you can — even using likely misspellings. That will give you control over any searches in your name.
— Write a blog on Tumblr and map your domain name on it. When you blog, do it as if you're at the local pub, not in a sequestered room.
— Register for as many profiles on as many sites as you can so that, as you grow your career, you can dominate as much of the first page as possible to develop your Klout score.
— Use About.me to create landing pages.
— A LinkedIn account is a must, but you can go the extra step and get a LinkedIn vanity name, so your name comes up in your profile's URL. It's a way to show attention to detail.
— Go through your previous online posts and delete anything irrelevant, frivolous or controversial.
— Don't misrepresent yourself.