Illustrator can only work on single page documents. Normally, you would need a page layout application, like QuarkXPress or InDesign to do multi page layouts. If you must use Illustrator for this, you'll have to create a new document for each side and print them seperately.
You could do some manual page make-up on a single document, but this really only applies to commercial printing, and even then it's not really practical in Illustrator.