There are several wonderful sites devoted to the era of silent films, and to early Hollywood in general.
One useful archive project is quickly becoming the most valuable library of vintage material and magazines on line. It is searchable and easy to navigate. Any fan of old movies will spend happy hours here browsing the articles and clippings:
The Media History Digital Library
And to stay up-to-date with news on current filmed Western adventures, movie stunt men, and more, check out
Henry’s Western Round-up
The Silent Film Still Archive
Here you can find original photos, advertising, lobby cards, sheet music and other memorabilia, much of it scanned from vintage studio materials.
This blog site is no longer active, but it still houses hundreds of posts on all aspects of silent film, with an emphasis on research.
The Golden Age of Hollywood
Located in the United Kingdom, this site specializes in biographies, filmographies and articles for the classic movie fan. Over 2500 pages of photos, reviews, trivia, screen savers and movie-related merchandise.