These tutorials include code for various different versions of Geotools including 2.0, 2.1 and 2.2. Some of the code might still work in recent versions of Geotools but, then again, these examples might not work. We are working (Summer 2006) to clear up this situation and develop a good set of tutorials for the 2.2 release.
to get you started coding
Tutorials that show you how to extend the capabilities of the geotools library: