Sports facility booking database

I'm writing a booking database program and the design of the underlying database is giving me some problems. The sports facility has multiple sites (different geographic locations) and the sports available at each site vary from one having a single tennis court to another having many tennis, badminton and squash courts. Time slots can be booked over the phone and need to be entered into an appropriate cell on the appropriate spreadsheet (VB MSFlexGrids).
My problem is trying to figure out the underlying structure of the database. A table for users (with name and ID), a table for sports available (badminton, tennis and squash), a table for sites (site name, court name)....errrm...
I just can't work out how to save the daily information such that the operator can check the database for who booked Tennis Court 3 at Site 1 between 10-11am a week last Tuesday?
If anyone could give me some pointers about how the timeslot table should be structured I would be very grateful.

-- 
Steve