Longicorn ID - A Tool for Diagnosing Cerambycoid Families, Subfamilies and Tribes. By E.H. Nearns, N.P. Lord, S.W. Lingafelter, A. Santos-Silva, and K.B. Miller
North American Lepturinae
Bug Guide - Allows any person to submit a photograph of an insect, which is then sorted and identified by a community of taxonomic experts. Specialists in certain taxonomic groups, like lepturine longhorn beetles, may search through images uploaded to bugguide to discovery new, previously unrecorded populations. Some photographers can be emailed for further information.
World Lepturinae
Photographic Catalogue to the Cerambycidae of the World - By Larry Bezark.
Coleoptera Neotropical - By Larry Bezark. Images of lepturines (and just about every other type of beetle) from Mexico to South America. Species images sorted by country.
Japanese Lepturinae
Madagascar Cerambycidae
Fenoscandia and Denmark - Google Book (partial preview)
Europe and Asia - cerambycidae.net
Lepturinae and Vesperinae in the Philippines - Salagubang,a website devoted to Phillippine beetles by Estan Cabigas.
Checklists
Checklist of the Oxypeltidae, Vesperidae, Disteniidae and Cerambycidae, (Coleoptera) of the Western Hemisphere. 2013 edition. n (updated through 31 December 2012) Larry G. Bezark and Miguel A. Monné, Compilers
Systematic list of Longicorn Beetles (Cerambycoidea) of the territory of the former USSR. by M. L. Danilevsky, 2013.
Checklist of the indigenous Cerambycidae of the Hawaiian Islands. by D. J. Heffern. 2002 version.
Checklist and Bibliography of Longhorned Beetles from Borneo. by D. J. Heffern. 2005 version.
Holotypes
California Academy of Sciences - type specimens from E. C. Van Dyke
Harvard Entomology MCZ Type Database
Smithsonian - Cerambycoid Primary Types
Literature
Cerambycoidea Papers - An extensive bibliography with PDFs of papers dealing with Cerambycidae and its related familes.
Biodiversity Heritage Library - Free digital scans of older books and journals, with many rare and difficult-to-obtain items.
General
Beetles (Coleoptera) and Coleopterists - Huge Coleoptera resource created in 1999 by the Coleoptera Department of the Laboratory of Insect Systematics of the Zoological Institute of the Russian Academy of Sciences.