1) Enable Caching - It will give a big improvement in speed. You can use either 'W3 Total Cache' or 'Wp Super Cache'. Make sure to configure them properly. 2) Optimize Database - You can use Wp-Optimize plugin for this purpose 3) Optimize Images - Use Wp Smushit plugin for optimizing images. Also make sure to use a good web host and a good theme.
you can use w3 total cache. Additionally you can follow other things mentioned on this post: http://webloggerz.com/how-to-speed-up-wordpress-website/
register your site with CDN google,.. join here https://developers.google.com/speed/pagespeed/service sign up and wait for they reply. good luck