I've recently had a book published about mixing with Waves plug-ins called Waves Plug-In Workshop: Mixing By The Bundle
Each chapter covers a different Waves bundle, starting withe the Musicians 2 bundle and progressing up through the Mercury bundle.
The first half of each chapter goes into detail about the new plug-ins introduced in that bundle. I also spend time talking about specific signal processing and mixing concepts as they are introduced by new plug-ins so that the book would be accessible to beginning engineers too.
The second half of each chapter talks about how to apply those plug-ins to a mix. You can download all of the individual tracks for a song I produced specifically for the book. Between those tracks and the downloadable Waves preset files you can get hands-on experience by following along.
I think this fits in really well with the MixOff ethos.
There is more info on the book up at Amazon