In a database with a list of periodicals, i have a table for categories. I have a query the allows the user to type in what category they are searching for. Is there a way in that query to provide a drop down box when it is launched rather than the "fill in the blank"?

You need to create a combo box on a form and then reference it in the query as criteria

i.e.

[Forms]![MyForm]![MyCombo]