I have been tasked with updating an existing Ning site, and have set up a Test Network - but many of the pages on the existing site have not been transferred to the test.
Is there a way to get all the content, or at least enough of it on each page to allow for editing?
The test network will not transfer in the custom pages you have added to your live site. That said, you can recreate these pages on the test network if you choose to do so. Here's more info about what will and won't transfer to your main site.
Garnor - is there a set of instructions for recreating the existing pages on the test network?
You can create these pages on your test site the same way they are set up on your live site. That is, by 'recreating' you are essentially setting them up again.