Making a Video Mashup

This is the first video mashup I have ever made.
It's called Jazz Penguin Mashup.
 
I made this mashup using clips I found on YouTube. I downloaded trailers from Mr. Popper's Penguins and Happy Feet 2 and a number of different files for the sound. Most of the music is various types of jazz. I used part of the music I made in Aviary from the last project for the intro music. This video contains entirely instrumental music. I choose not to use any songs with words.
This video was made using FileLab on the web. I found the most difficult parts to be splitting the music at the right spot since I had no visual cues to know where to make the split and trying to get the music synced to the video. I don't feel that I got that part exactly right. Also some type of transition between the various music in the mashup would help, but I don't know how to do that either.
Anyway, I hope you enjoy it.