There's a printed magazine Swara Bendhe devoted to Australasian gamelan - subscription form (PDF).
Its history and role in modern society - The Indonesian Language
limited freedom of religion in Indonesia - JakartaGlobe
Some Javanese gamelan notation (prepared by Vi King Lim for Langen Suka).
Forthcoming review: Richard Pickvance's superb A Gamelan Manual
Andrew Beatty - Varieties of Javanese Religion
Judith Becker - Gamelan Stories: Tantrism, Islam, and Aesthetics in Central Java
Clara Brakel-Papenhuyzen - Classical Javanese Dance: the Surakarta tradition and its terminology
James Brandon - On Thrones of Gold: Three Javanese Shadow Plays
Benjamin Brinner - Knowing Music, Making Music: Javanese Gamelan and the Theory of Musical Competence and Interaction
Alit Djajasoebrata - Shadow Theatre in Java: Puppets, Performance and Repertoire
Margaret Kartomi - The Gamelan Digul and the Prison Camp Musician Who Built It
Niels Mulder - Mysticism in Java: Ideology in Indonesia
Other SitesIf you are after a general gamelan discussion list, check out the gamelan-l mailing list.