Here’s the presentation for the Classification topic:
Follow the links in the images to learn more.
There’s a good wiki article on Classification here.
Here are some decent links to free organism identification resources:
Rapid Color Guides do loads of pdf files on tropical plants, lichens and animals.
The Mekong River has been extensively catalogued in terms of invertebrate life.
Riverwatch has a more user-friendly identification guide, that goes to Order level.
You can even carry out a virtual rocky shore transect from the British Ecological Society.
And there are a load of awesome resources at the UCLA OceanGlobe Student Resources site.