I’m so confused on relationships in Access 2007

I am creating a database to track expiration dates for our clinicians. I have 3 tables: Staff (with demographics), Event (lists the different types of items we need to track. I.e., license, in-services, etc. and the last table is Event Entry that has a drop down for staff and description and a 3rd column to add the expiration date. I need to connect them somehow.