youeverysecond on "Site very long to load"

Hi,
My website http://www.youeverysecond.com takes a loooong time to load. When I test it with pingdom it usually says more than 6 seconds, and like 80% of the time is spent on "Wait" time. What is this exactly and why would it occur?
Please could you help me solve the problem?
I have also enabled the page load time metric in my Google Analytics and some pages even reach more than 13s page load on average... (for example http://www.youeverysecond.com/be-grateful-now)
Any clue?
Nicolas.