Hi Bob,
Sounds as though the problem isn't with the pictures, it's the fact that the sites aren't already listed - apologies if I'm misinterpreting your post. If the sites aren't on TMA, you can't add photos or fieldnotes, etc until you've added the site itself to the appropriate county.
Go to the county/region - if it's Exmoor you're talking about, make sure you select the correct couty (either Devon or Somerset). Once you're in either "Exmoor (Devon)" or "Exmoor (Somerset), you should see a horizontal grey band about a third of the way down the screen (depending on browser settings) with a drop-down menu, select the "Add a site" option and give the details (e.g. map reference, type of site, etc).
Hope this gets you somewhere!