In our first PET class I gave a swift presentation about the methodology, contents and parts of the test with a power point which you can find below:
Powerpoint PET
Book: 978-0-521-17485-5 Preliminary for Schools Trainer Six Practice Tests without Answers.
Here you can find the list of the grammar contents with exercises online:
Here you have the list of the vocabulary in case you want to look at it in advance:
Welcome to this new challenge!!