This guide is intended as a very brief introduction to the fascinating world that can only be seen under the microscope. A future guide will go into more detail about collection, classification or storage. Sediment samples and prepared slides can sometimes be found for sale among my listings on eBay but there are a few other sellers out there; I am a qualified micropalaeontologist and would be happy to answer any questions about microfossils.
Since plant microfossils such as diatoms or pollen need more complicated preparation, for the purpose of this guide "Microfossil" means either a Foraminifera or an Ostracod. There are many thousands of species, identified by sometimes very minor differences. Many specimens can be housed in a single slide (try a UK based company called Biotec for microscope slides suitable for microfossil work).
Foraminifera are marine single celled organisms with a gelatinous or a hard calcareous or agglutinated shell (called a test). If the foram lives on the sea bed - it is Benthonic (American spelling - benthic), if it lives near the surface - it is planktonic (planktic).
The family Ostracoda are more complicated - related to crabs & prawns, these small crustaceans have a bivalved shell (called a carapace; one part is a valve). In the fossil record, they are split into species using differences in the size, shape and ornament of these shells but the scar left by the muscles that opened and closed the valves are also used. Ostracods have a much wider range of habitats than foraminifera - shallow to deep sea marine, rock pools, salt marsh channels, estuaries, ponds and lakes, up trees and in damp soils, as well as in rice paddies & drainage ditches!
In summary: there is a lot to be said for studying microfossils but a word of warning - it can be disastrous when you SNEEZE!!