[Plugin: google-shared-contents] Installing

* download google-sharings.zip file and unzip it. Than put the unziped folder into “wp-content/plugins/” folder.
* activate the plugin from your WP control panel.
* Type your Google ID and the content count number will be displayed on your site by clicking “Options“, than “Google Sharings” from your control panel.
* than modify your theme’s any file (depending on your choose where to display it) you want by adding the lines below:

<?php if (function_exists('load_google_sharings')) {
load_google_sharings('defined'); } ?>

http://wordpress.org/extend/plugins/google-shared-contents/