In order to make a double page spread I set up my document as a single page then go to Pages and make it a double page by clicking on Master page.
When I want to export it as the new double page only one (usually the second page) will go.
You also need to go to Document Setup and make the file Facing Pages....
This might help to expand on what Peter has said: InDesign Help | Create new documents
Retrieving data ...