BEAST (Books, Ebooks, and Articles Search Tool) is EPFL’s comprehensive library search engine.
Virus Pathogen Resource (ViPR) compiles useful information about genomes, proteins, SNPs, host factors, antiviral drugs, and more, along with many tools for sequence analysis.
ViralZone offers lots of well-organized facts about different viral families and genera, detailed information about their replication cycles and molecular biology, sequence information, etc., and all is beautifully illustrated.
Viral particle explorer contains useful information on viral structures, including pdb files for full and half capsids.
This Week in virology (TWiV). A fun podcast on various topics of virology, produced by Prof. Vincent Racaniello and others.
Virology 101. A useful course that covers the basics of virology and relevant experimental techniques. Contains episodes of TWiV.
Virology toolbox offers useful explanations for the most important experimental techniques related to virus culturing, enumeration and molecular biology. The site also contains introductions to different bioinformatics tools.
Nextstrain tracks virus evolution in real-time. Very cool!