How do I create a query that populates a combo box?

I am new to Access and have been tasked with creating a simple database for work.

Using Access 2007.

Searched the forums and seem to have found complicated details for combo boxes that are out of the scope of what my simple database will need.

I have a table with 3 fields, Badge#, Last, and First name.

--on the form...

I want to be able to select the last name of a person entering a server room.