Scott Joplin International Ragtime Festival, in Sedalia, MO. Joplin made his home there in the late 1890s.
Ed Berlin gives annual lectures at the cemetery in Queens, NY where Joplin was interred. His website includes information about his books and links.
RagPiano.com - developed by ragtime pianist and historian Bill Edwards. Lots of great stuff, including his 40 CDs, authoritative links, and information and covers on Joplin's music divided into two periods, 1895-1905 and 1906-1917.
The Scott Joplin House State Historical Site in St. Louis and Friends of Scott Joplin.
The Regional Music Heritage Center in Texarkana, TX is dedicated to the music and lives of Scott Joplin, Conlon Nanarrow, Paul Klipsch, and boogie woogie.
David Beck has lots of information on rolls, free scores, and recordings on his site.
Rag's Rag - player piano rolls recorded during the ragtime era, with recordings and scores of piano and ensemble arrangements from major ragtime composers.
Ragtime Outstanding Achievement Award
The Swedish Ragtime Home Page
West Coast Ragtime Society