Firstly you need to create and link the accounts for you to be an author:-

Visit this link: http://support.google.com/webmasters/bin/answer.py?answer=1408986&hl=en

You can link content that you publish on a specific domain (such as www.wired.com) to your Google+ profile.1.Make sure that you have a profile photo with a recognisable headshot.
2.Make sure that a byline containing your name appears on each page of your content (for example, “By Steven Levy”).
3.Make sure that your byline name matches the name on your Google+ profile.
4.Verify that you have an email address (such as stevenlevy@wired.com) on the same domain as your content. (Don’t have an email address on the same domain? Use this method to link your content to your Google+ profile)

Submitting this form will add your email address to the Work section of your profile, which by default is viewable only by your circles. You can keep your email private if you wish. It will also add a public link to the domain of the email address to the Contributor to section of your profile.

For more information:- https://plus.google.com/authorship#authorship