The Department of Engineering Teaching Office website has a section dedicated to Information for Offer-holders - http://teaching.eng.cam.ac.uk/information/all/offer-holders/content

Please look specifically at the following pages:

Preparatory Problems - https://www.vle.cam.ac.uk/course/view.php?id=83271

Preparatory Programming (this is a separate section of the above Preparatory Problems) - http://teaching.eng.cam.ac.uk/content/preparatory-programming

Lego Mindstorms flyer - http://teaching.eng.cam.ac.uk/content/preparing-lego-mindstorms-exercise-download

Advice for Freshers - http://teaching.eng.cam.ac.uk/content/advice-freshers-0