They call it a desktop course, but on a quick scan it looks like a handy reference for all things Ubuntu. Free download of pdf.
Link: https://lists.ubuntu.com/archives/ubuntu-training-support/2007-December/000077.html
Edit: On a second look, it seems to cover desktop usage, and not lower level stuff, but should still be handy for those thinking of making the jump from windows to get up to speed faster.