[Zope] cacheing zope

Hello, I am looking for info on how to use * RAM Cache Manager* *** Accelerated HTTP Cache Manager* ** I am using Zope 2.7 How do I interpret the numbers in the Statistics? I have a Ram Chache and get rather lot of misses. How can I improve the hits ? What I want to improve is a plone site. Much of the time (as I can see from a profiler) is spent in creating the news list. However this list is nearly static (only every couple of days any changes). How can I improve that ? thanks for your info Robert