Conrad First — The Joseph Conrad Periodical Archive
http://www.conradfirst.net/

This is an open-access archive of the serials that first published Conrad’s many short stories, articles, novellas, and novels.  This site allows you to see the different contexts in which Conrad’s now canonical works first appeared.  You can read the articles that appeared alongside Heart of Darkness when it was published in Blackwood’s Magazine, for instance, or see what advertisements surround the text of Nostromo when it appeared in T.P.’s Weekly.

The Joseph Conrad Society (UK)
http://www.josephconradsociety.org/

Here you can find access to the Conradian, a scholarly journal on Joseph Conrad’s work, as well as a Conrad bibliography and reviews of monographs on Conrad.  Perhaps most useful is the “Student Resources” section, which contains a critical introduction to Heart of Darkness as well as links to other interesting sites dealing with the masterpiece.