What Websites Have Image Libraries for Bacteria and other Microorganisms
While I doubt that this might be possible in all cases (and I would be careful about classifications), there are indeed some great ressources, which contain a lot of images. Since there is a vast number of bacteria present on this planet, there is of course a limitation to bacteria available in photos, representing only the most common or important.

These are:


Bacteria in Photos
American Society of Microbiologies Microbelibrary
Microbiology in Photos


Then there is an information page available from the CDC, which informs about parasitic diseases. These are non-bacterial, but probably also interesting. It can be found here:


Laboratory Identification of Parasitic Diseases of Public Health
Concern