Plugins an performance issues

I am in the process of launching this site https://news.fiu.edu/ it was a bit slugish in localhost but I assumed that would approve when I moved to production but it did now. I do have a number of plguins running on this site many of which make calls to external services like google analtyics, facebook, twitter, flickr, youtube etc. It many times loads like a dog any idea of how to improve the performance?