All things Palo Alto Networks
Welcome! AFAIK there's no books out yet, so I decided to write one ;) stay tuned for august 7 on https://www.packtpub.com/cloud-networking/mastering-palo-alto-networks or Sept 9 on Amazon https://www.amazon.com/gp/aw/d/1789956374
Look forward to it, thanks reaper.
But do feel free to ask any and all questions on the forum :)
I'd suggest hands on tinkering with the equipment if you have that ability, combined with the educational material available through PANW (https://www.paloaltonetworks.com/services/education) and fuel (https://www.fuelusergroup.org/page/palo-alto-networks-101).
fuel membership also includes free lab access - https://www.fuelusergroup.org/page/fuel-virtual-test-lab-8.0.