Some useful tips

Video and audio

http://audacity.sourceforge.net/

Free software

Tutorials available on YouTube

http://youtu.be/21wh0iixiDA

Audacity

Audacity

http://www.acoustica.com/mp3-audio-mixer/

Free 7 day tial.

Easy and simple. Add sound. Move sound. Save as a sound file.

Demos at : http://youtu.be/IohOfT2fjE0

Acoustica mp3 mixer

Acoustica

Go to http://windows.microsoft.com/en-GB/windows/downloads/get-movie-maker

Very simple and user friendly

Windows Live Movie Maker

Settings

Video manager

http://www.youtube.com/

YouTube video editor

More expertise needed.

Final Cut Pro

http://www.slideshare.net/

Slideshare