Install Social Like/Share and Auto Publish Extension/Plugin on Joomla Site

I have a Joomla created website that needs to be connected to my Twitter, Facebook and Google +1 website and perhaps others. I am having trouble understanding which is the best Extension/Plug-in to use and more difficulty installing it to it works. I already think I have gotten it so people can Like and Share but can't get it set up so that when I publish an article on my website, it automatically publishes on Twitter and Facebook etc. I don't know if I have the proper extension as the language is difficult to understand given my lack of competence in this area. I am sure this is an easy task for someone but it's a challenge to me and I am out of patience. I will learn how to do it based upon your finished product. I am doing this because I have come to understand that I cannot build solid SEO without tying Facebook, Twitter and others to my website and building a social network of followers. Thanks