Could you give us some idea of what the projects about? What are the directions?
Linking to other websites that sells livestock, or has a competing message board is not allowed here. I recommend you either delete that post, or edit the link out. Even though I enjoy that place, the rules are the rules.
I would ask your son exactly what the directions of the project is. Tell him to give you as much details as possible. Make sure you're clear about this project, and the directions for doing so. Until then, it's going to be very hard to give you any links. Saying 'Coral Reefs' is quite general, as there are hundreds of existing reefs with many species of corals.
Here's a few websites that I got from a few quick searches: www.encarta.msn.com (Great Barrier Reef) www.australiageo.com www.earthisland.com http://www.ozramp.net.au/~senani/barrier.html