There is now an excellent "Intro to Mixbus" video available for $19.99 from Harrison Consoles. Although it obviously covers some Mixbus specific techniques, a lot of its 2 hour length is completely applicable to users of Ardour.
The video CAN be played successfully on Linux although you may have issues depending on which video playback software you use, and which video codecs you have installed. Successful playback has been noted using VLC and MPlayer. A more portable transcoded version might be available in the future.
Produced by Nathan “Adan” Adam of AdanAdam.com and Multi-Platinum.com, this HD video download features in-depth overviews of the Edit and Mixing system, Power-user tricks, Keyboard shortcuts, Compression settings, Recording and Automation.
Other Topics Include: Playback & Editing Options, Right Click Tricks, Plugins, Inserts & Sends, Tape Saturation & Mix Busses, Punch Ins & Outs, Nudging, Splitting, Meters, Tempos, Snapshots, Solos, Crossfades, Ranges, Gain Automation, Duplicating, Muting, Exporting, Filling, Spliting, Arming, Routing and so much more...
If there is enough demand, there may be future videos from Adan specifically targetting Ardour.