Jim Zwick's Mark Twain Resources — a remarkably detailed collection of online Twain resources.

Life and Works of Mark Twain from the Hannibal Courier Post site — wealth of information including newspaper archives.

Mark Twain at Berkeley — previously unpublished works.

Mark Twain Forum — comprehensive book reviews

Mark Twain House and Museum is both a valuable online resource and an ideal location to include on your itinerary if you are planning a visit to Connecticut.

Mark Twain in His Times — from University of Virginia.

Mark Twain's Mississippi River — from Northern Illinois University — includes video interviews with Gregg Camfield, Shelley Fisher Fishkin, and Robert Hirst.

R. Kent Rasmussen's site — author of Mark Twain A to Z and other notable Twain books with information on collecting Mark Twain volumes.

Studies in American Humor — full text journal articles from renown Twain scholars on a variety of topics.

TWAIN QUOTES: If you're looking for a memorable Twain quote to include in your next speech, look no further than this excellent collection of quotes.

Union Catalog database of letters written by and to Sam Clemens — searchable reference tool.

The Ballarat Mechanics' Institute in Victoria, Australia — has an extensive and historic collection of reference books, some of which are listed on the site, plus an up-to-date lending library of contemporary titles.