YouTube - UsingMoodle's Channel
Lots of great tutorials for Moodle
Imported from Diigo
eFront: Top 10 Open Source e-Learning Projects to Watch for 2011
Great collection of open source e-learning projects and tools, including multimedia development, screen recording, Android app development, an LMS, and more. (Technically, some of these are Free, not Open Source, but still a valuable list.)