Oceans & Coasts

"NatureServe Explorer provides conservation status, taxonomy, distribution, and life history information for more than 70,000 plants, animals, and ecological communities and systems in the United States and Canada. The data available through NatureServe Explorer represent a “snapshot” of the U.S. and Canadian data managed in the NatureServe Central Databases. These databases are dynamic, being continually enhanced and refined through the input of hundreds of natural heritage program scientists and other collaborators.

BugGuide is a wonderful collection of images of insects, spiders, and other arthropods, grouped into their taxonomic categories all the way down to the species level. These people know their stuff and can help if you're stuck trying to identify a specimen. It helps to have a little knowledge of how these animals are organized before you start, however the search feature works well too.