How to approch new books?

[mead50]

I just got 2 new books

4-Way Coordination
&
The New Breed

Should I learn one, master it, then move to the other book, or spend equal amount of time on both?

[blade123]

Work on both of them at the same time.
If I stay with one book until I mastered it, I would have a grand total of 1 book. You will never truly master a book (unless it's BAD, or you have no imagination). You will always find new ways to use a book. Syncopation is a great example. Once you can play through the book, that doesn't mean you've mastered it. Can you play each pattern on your snare while swinging? Can you play each pattern on the snare over a left foot clave and the cascara pattern on the ride? Can you play the patterns with your feet? Can you play the patterns at 250 bpm?
Any good book can and should be taken out of context.