Google Add to Circle is a free wordpress plugin to display and to add your Google+ Page to their circle directly from your website.
Login to wordpress (wp-admin).
In your admin dashboard click plugins and select Add New.
Type Google Add to Circle in the search field and click Search Plugins button.
Install Google Add to Circle.
After the successfully Installation click the activate Plugin link to activate the plugin.
Download Google Add to Circle wordpress plugin. Download link.
Unzip and upload it to your WordPress wp-content/plugins directory.
Login to wp-admin. In your admin dashboard click plugins and activate the Google Add to Circle wordpress plugin.