HOWTO: Add pictures to a cache listing
Here's a quick and dirty tutorial on how to add an image to your GCA cache listing.
Create your cache listing and save it.
To the Right of your caches page you will see the option 'Add/Edit gallery' under Owner actions.
Select 'Add another item to this cache'
Upload all the Images you wish to use for the cache listing.
Go back to your caches page, and you will now see a 'Gallery' section below the description
Click on 'View Gallery items for this cache' and then click on the picture you wish to use in the cache listing.
You should now see a full size version of the image
Right click on the images and select 'Copy image location'
GO back to your caches page and edit the listing
type: <img src='paste your images location_here'> eg: <img src='http://gallery.geocaching.com.au/pics/ga0452/272.jpg'>
Save it and you should now see an image in your caches listing!
It's a little agricultural right now, but we'll be improving on this in a future release
Additional notes for geocaching.com listings
The best place to host your photo is on the listing itself. That way you know it'll remain available for the life of the cache, and will survive changes of ISP and the like.
So, upload the image, then look at the listing to see the link to it below your text. (You might have to refresh the page a couple of times, it can take a few moments to appear.)
Copy that link. In most browsers it's something like (right click), copy link location. You'll figure it out!
Now, edit the listing and make sure "The descriptions below are in HTML" is ticked.
Use the details in the using html page for adding line and paragraph breaks and for inserting your image(s).
Don't use the instructions for background images, though! There's a box in the edit page for you to paste the URL of your background image; use that instead.