Florida State University
Florida State University: Virtual Microscopy
These interactive tutorials allow you to adjust the magnification and focus of the object. Requires Java.
Other
Science Stock Photography
This site has numerous pictures of microscopic images. It also has a search engine so you can find specific objects. Images were captured with light microscopes, as well as electron microscopes.
Lawrence Berkeley National Laboratory
Berkeley Lab: Ncem: Electron Micrographs
This site contains a gallery of scanning electron micrographs of non living substance.