I am having trouble with site speed, see screen shot. How

Hello,
I am having trouble with site speed, see screen shot. How can I improve it? What plugins? I added some plugins to my other site, shop.chuckroy.com and caused some of the marketpress functions to break. Google site speed recommends:
-Eliminate render-blocking JavaScript and CSS in above-the-fold content
-Leverage browser caching
How do I get this done, thanks?