Free sample tests!
http://exams.richmondelt.com/index.php?practice_tests_pet_en
http://olpt.s3.amazonaws.com/online-practice-pet/index.html
http://eslcommunity.org/cambridge/pet-tests/pet-for-schools-practice-test/
https://sites.google.com/site/programabeda/home/alumnos/pet/pet-materials
https://clilcolonna.wikispaces.com/PET+Listening+Practice

Brilliant webpage!

http://learnenglish.britishcouncil.org/en/word-games/verb-machine
http://learnenglish.britishcouncil.org/en/elementary-podcasts
http://learnenglish.britishcouncil.org/en/talk-about
http://learnenglish.britishcouncil.org/en/stories-poems

Learn by doing tips
http://learnenglish.britishcouncil.org/en/how/how-order-round-pub
http://learnenglish.britishcouncil.org/en/how-to
https://www.youtube.com/watch?v=bjfM4Wrj9UI
http://en.wikipedia.org/wiki/Shim_Sham

Listening tests

http://englishaula.com/en/pet-exam-listening-cambridge-preliminary-english-test-video-lessons-practice-tests-exercises.php

Interesting reflections on learning a second language.

http://www.youtube.com/watch?v=nCpT9bi8zSc&feature=channel
http://www.youtube.com/watch?v=rGVNbkGFrNM

Stunning web brimming with very entertaining activities organized by semantic fields. Exercices revolve around short textsthat students have to listen to. Activities include listening, matching vocabulary, spelling words after listening to them, et cetera.

http://www.cdlponline.org/index.cfm?fuseaction=homepage