What exactly do you want from the Pages program? If you want the layout of the page with the items arranged side by side, etc, then yes, PDF is the proper way. But you won't be able to edit the PDF in the ID document. If you want to start with the plain text (preferred) and then format and arrange it in InDesign, you'll have to export the text from the Pages document. I don't know the formats that Pages provides, but if there's an RTF (rich text format), then that's the one you want.
You can also export MS Word format which will let you import the Pages style sheets when you place the document in InDesign.