Help

Hello i am trying to put my freeradius server to work as follows i need a group of user let say group A i need they can connect 1 hour daily and 25 hours mounthly with a session-timeout of 30 minutes second group of user let say group B with 50 hours mounthly and no daily limit and another group without any limits I know probably this is realy easy to do but i am trying to understand how freeradius works i will like to know if any one knows a realy good handbook of freeradius Thank in advance