The best easy and free video editing software available is Shotcut

I've never editing a video before, but I needed to yesterday. I found Shotcut, and I couldn't be happier about how easy it is to use. It's free, easy AND it's a portable app, so you don't have to install anything. They've got a very active forum and tons of how-to videos available. If you need to do some video editing (including multiple tracks, audio overlay, and all the high-ed options), give it a try.