Kourosh Dini (@Kourosh), who featured in MPU 78, 263 and Free Agents 40 has released an updated version of his OmniFocus book: Creating Flow with Omnifocus 3.
A table of content is available here (source)
The @MacSparky OmniFocus Field guide refers to this (upcoming) book in the additional resources section.
I have the preceding version (v2) of the book, which I consider to be very extensive and with implementable examples. I will be buying the new version!