Good software for a simple, slide-show style video presentation? So we have to make a short video (Less than 5 minutes) for a leadership course as part of our degree. (Engineering)

We're not really video people, so we've decided to simple slide show style video (Using something like Prezi, so that it at least looks and feels somewhat proffesional) with some voice-overs (which we've already recorded.)

Can anyone offer any suggestions for a simple piece of video edition software that's free? I don't need anything too feature rich, just something that can let you mix visual with audio and is quick to learn?

(Also, as a quick aside, can someone suggest background music that's generic and vaguely inspiring?)

Edit:
Posted my own answer, but still chose Vladislav's answer because it was good. Also, Youtube Audio Library was awesome. Best background music ever. Thanks.
So, I ended up using Prezi to run a presentation and camtasia studio to record it and render it to the video file I needed. Both were 30 day free trials, so that worked out nicely. 

I put all the audio in Prezi (It lets you add background music for the whole presentation as well as voice overs on a slide-by-slide basis) but I could have just easily have done it in camtasia.

I needed the voice overs for timing in the Prezi, which is why I did it that way, but there's nothing stopping you from just putting them in anyway, and removing the sound when it gets to camtasia, and putting them in as separate tracks. You'd probably have better control of volume, etc, that way.