Musical Artifacts A very useful (and unique!) website designed to help "catalogue, preserve and free the artifacts you need to produce music." Lots of presets and sample material available gratis for download.
Audio4Linux Another good resource for linux audio production, with active forum and lots of links. In German.
LinuxAudio.org A very useful linux audio production website, including useful links to free sampled audio files.
JackAudio.org Useful realtime-scheduling configuration reference for Jack audio in linux.
Libre Music Production A very up-to-date resource with lots of articles, interviews and tutorials on music production with the linux OS.
Making LV2 presets A nice article about making presets, by Freesoftwaremusic.
Musically.me.uk Folderol's website, with lots of interesting music utilizing Yoshimi.
LinuxMAO.org A good linux audio production portal, in French.
Linux-4-Music Lots of reviews, videos and links for linux-loving musicians! (The linux4music.co.nr link redirects to the developer of Triceratops.)
Zthmusic.com A very resourceful, up-to-date website about everything linux and audio production: interviews, reviews, reflections, tutorials and...music!
Linuxmusicians.com A good place to ask questions, get help with your computer's audio configurations, etc..
LinuxAudio System Configuration This page is crucial to understanding some basic adjustments that will make your linux system perform at speed. Several areas are dealt with, including swappiness, adding your user group to specific files, and realtime kernel installation.
Wikipages of Linuxmusicians.com A whole lot of information about audio production using linux, including how to make your computer work as a realtime audio processor, for maximum performance.
Linux Audio Forum at Nabble.com Another useful forum to discuss and find help about issues regarding digital music production with Linux.
Linux-sound.org Similar to the wiki link above, lots of links here too. (Nice list of virtual linux-based synths at the "software synthesis and music composition" link on the left.)
KXStudio at LinuxAudio.org The website for the KXStudio project: a very nice addition to install on top of your debian operating system. It has all the works, and is constantly undergoing new developments and additions.
linux.autostatic.com A whole lot of information coming first hand from a seasoned linux-for-audio-production guru!
Music, Programming and a Cat Various topics about making music with open source software, making music open source software-- and a cat.
Anthony Deaton, composer and guitarist A nice website with some very nice guitar work and arrangements utilizing the linux platform.
Laborejo-Music Notation Workshop Laborejo, Esperanto for "Workshop", is used to craft music through notation. It is a graphical user interface for Lilypond, a MIDI creator and finally a tool collection to inspire and help you compose.