The text of sample chapters is available, too. One stop shopping for mycology. This phylogenetic navigator provides a tree that shows the evolutionary relationships of living organisms, including fungi. It also supplies descriptive pages on selected terminal taxa. Like biological systematics itself, it's a work in progress.
Similar introductions are available for all other taxa.
This link makes a valuable addition to any teaching program. University of Tennessee Mycology Labs Drs. Ron Peterson and Karen Hughes maintain a nice set of web pages that include a primer on Botanical Nomenclature, a synopsis of molecular phylogenetic techniques. Lots of information is also provided on the projects of staff and students. An illustrated history of news coverage of the Irish Potato Famine that occurred in the 1840s due to Phytophthora infestans , causal agent of late blight of potato.