Hey so you want to make a book trailer. The best way to start software wise is more than likely right on your computer it's called. Windows Movie Maker, and it has some great transitions, and some cool things to add to your trailer. I'll also be adding some other suggestions from other Indies. My two favorites are Windows Movie Maker free on most computers. Wondershare, it cost me about 80 bucks but I make a lot of videos. Below in some more threads will be other options.