Had the same problem with the ADV Riders forum.
Posting photo's one at a time is easy but if you need to post a load of photo's, the easy way is to open an account with Smugmug or similar (US$30.00 per year).
It's so easy that even a luddite such as myself can manage it. We went for a ride around the Cotswolds on Easter Sunday & a few local villages on Monday, taking quite a few photo's. I posted all on to two Smugmug galleries, they're not in order yet but have a look at the link. There are are cheaper sites available but you're limited on file size etc. Follow this link:
I've e-mailed Smugmug re: photo order & they've advised me how to do it, which I'll do later. These galleries work with only one photo.