Moz - go here http://www.themodernantiquarian.com/site/5309/channel_islands.html and choose your island, then you should be able to use the drop down to pick "add site", name it, choose site type and location, and you're away. Now navigate to the site and you'll find the option to add images, field notes etc - if you encounter any difficulties, post back here or mail the eds [email protected]
Good luck!
Sals