Along with Adam Anderson, I co-wrote a prep book for the Physics GRE, "Conquering the Physics GRE." The full print edition is available on Amazon. Our website has errata sheets and individual chapters and practice tests in PDF form available for purchase.
The Revised Third Edition will be published by Cambridge University Press in winter 2018.
Below, you can find a webinar I gave for the American Physical Society with some tips for GRE preparation.