Below is an ongoing compilation of well-constructed websites that contain a wealth of additional information on trilobites:

Trilobite Background	Museum & Private Collections	Stratigraphy, Geology & History	Preparators and Vendors
Trilobiteame: Trilobites of the Iberian Peninsula Enrico Bonino's website on early Metazoan Paleontology including his brilliant new book on trilobites Trilobites of Morocco Moroccan Trilobites of Alnif More Moroccan Details A Guide to the Orders of Trilobites Trilobites of Eastern North America The Xiphosura The Paleobiology Database Walcott-Rust Quarry Western Trilobite Association Klub Conocoryphe Cincinnati Dry Dredgers Wikipedia-Trilobite Encarta - Trilobite New World Encyclopedia - Trilobite AllRefer, Reference - Trilobite Fossil Facts and Finds Fossil News - Journal of Avocational Paleontology Collecting Fossils Largest Trilobite	Back to the Past Museum The Largest Trilobites are found in Portugal Royal Ontario Museum Museum of the Earth (trilobite collection) Trilomania Blog Eric Bonn's Trilobites Bedrock Bugs Virtual Fossil Museum Fossil Collecting in the Arbuckle Mountains Extinctions House of Phacops Mark Marshall's Collection Robert M. Hazen Geophysical Laboratory - Trilobites Museum of Comparative Zoology, Harvard - Trilobites LeGrand Smith - Bolivian Trilobites Rhenohercynian Trilobites Trilobites from the Ardennes-Eifelregion Devonian Trilobites Per Hansson's Trilobite Gallery Among My Trilobites Bob Schacht's Collection - Trilobites Trilobita.de Mark Bourrie's Collection - Canadian Trilobites Yale Peabody Museum - Trilobite Gallery Collecting Fossils - Moroccan Trilobites Trilotarium Earth Science World Image Bank Mark Burrie's Canadian Trilobites	Peripatus - Devonian Period Oklahoma Geological Survey Oklahoma Geology and Paleontology Devonian Times Phanerozoic History - Animals Phanerozoic History - Plants Hunsruck Slate Geologic History of Nova Scotia The Paleontology Portal - Fossil Gallery International Stratigraphic Chart GeoWhen Geologic Timescale Paleozoic Timescale and Sea Level History Geologic Map of the World	Most of the sites below are more like museums than vendors, but the images are subject to more frequent change. Black Cat Mountain Trilobites Paleo-Prep American Trilobite Suppliers Gold Bugs Extinctions St. Petersburg Paleonotological Laboratory - Russian Ordovician Trilobites Marc Behrendt Fossil Preparation Trilobite Shop Association of Applied Paleontological Sciences (AAPS) Paleo Direct - Trilobites Preparator's Resources, Society of Vertebrate Paleontology
Cyphaspis carrolli (photo courtesy of Sam Stubbs and Neal Immega)