Google +1 WordPress plugin adds the Google +1 button to your wordpress site.
Main Google + Plugin Features:
vote using the cool Google +1 button
Google +1 widget
choose which posts and pages are included
4 button sizes
Show/hide Google +1 counts
Customize position of the button
Shortcodes and styling
Google +1 button FAQ
1. Download Google +1 WordPress plugin. Download link.
2. Unzip and upload it to your WordPress wp-content/plugins directory.
3. Login to wp-admin. In your admin dashboard click plugins and activate the Google +1 WordPress plugin.
4. Then go to Settings menu and select Google +1.
5. select button appearance,position,language and show +1 count and click Save changes.
To add Google +1 button manually click Here