There's a host of book trailers to look at on the World Book Day website. Book trailers are like film trailers - they give you a good taste for the book. The standard of cinematography is superb, so check out the full list by clicking here.
Look at the "Flip" book trailer by Martyn Bedford. According to goodreads.com, "one December night, 14-year-old Alex goes to bed. He wakes up to find himself in the wrong bedroom, in an unfamiliar house, in a different part of the country, and it's the middle of June. Six months have disappeared overnight. The family at the breakfast table are total strangers. And when he looks in the mirror, another boy's face stares back at him. A boy named Flip. Unless Alex finds out what's happened and how to get back to his own life, he may be trapped forever inside a body that belongs to someone else. Questions of identity, the will to survive, and what you're willing to sacrifice to be alive make this extraordinary book impossible to put down."
[Video: www.youtube.com]