You need to take the Glock armorers course to get the certification. Check out http://www.glocktraining.com/ for more info on how to sign up but note that if you aren't an LEO, or military, or a GSSF member you can't register. Fortunately it's easy to join GSSF.
Book wise all I have is my armorer's manual and the latest version is pretty nice. You just need to take the class to get it. Totally worth it even if it is easy as hell to work on a Glock.