The following is a snippet to add a "share" or "bookmark" button to social media sites - using addthis.com
<!-- AddThis Button BEGIN -->
<script type="text/javascript">
var addthisJsHost = (("https:" == document.location.protocol) ? "https://" : "http://"); document.write(unescape("%3Ca class='addthis_button' href='http://www.addthis.com/bookmark.php?v=250'%3E%3Cimg src='" + addthisJsHost + "s7.addthis.com/static/btn/v2/lg-share-en.gif' width='125' height='16' alt='Bookmark and Share' style='border:0' %3E%3C/img%3E %3C/a%3E")); document.write(unescape("%3Cscript src='" + addthisJsHost + "s7.addthis.com/js/250/addthis_widget.js' type='text/javascript'%3E%3C/script%3E"));
</script>
<!-- AddThis Button END -->