The definitive home of Coleridge information on the Web. Marjorie A. Tiefert at the University of Virginia did seriously good work here. Worth noting is the dictionary that translates words in Coleridge's vocabulary that are rarely used in ours.
This website is a helpful introduction to the Romantics. Start with their overview to the Romantic era and then move on to the individual biographies of Coleridge, Wordsworth, and other major players. Links to the poems and critical essays about Coleridge are also available on this site.
The only requirement for membership in the Friends of Coleridge, a U.K.-based non-profit, is interest in the life and works of Samuel Taylor Coleridge. You can attend conferences, learn about Coleridge-themed events, and take a virtual tour of Coleridge's former home in Nether Stowey.
Coleridge is a challenging read, and so it helps to hear what other scholars have to say about him. This site has an index of critical essays and reviews about Coleridge, all of which are available online. This is a helpful guide to secondary sources if you're doing an in-depth paper on Coleridge.
The e-text warehouse Bartleby offers the Coleridge entry in Bartlett's Familiar Quotations. It is helpful for choosing quotes or passages to study further, but don't use this page to bluff your way out of not having read "Christabel."
Friend Samuel Taylor Coleridge! His Facebook page is a quasi-international meeting place for Coleridge fans scattered around the world. Join one of the ongoing discussions if you can't get enough of your favorite Romantic poet. (Just don't unfriend him—Coleridge took slights hard.)