What you need is the following : 1) Download Windows Movie Maker Here
Using windows movie maker is simple, its like a timeline and you basicaly upload the video footage there and drag in the places you want it to be shown, you should add music also -> drag music in the timeline.
2) Download Fraps Here
I use fraps to record the footage ingame, you just have to pick a key you press and in the corner it will show a number which when you press the certain you choose it goes red and you have about 60 secs or recording, that all goes into a fraps folder which you can drag into or uplaod in windows move maker.
Thats all I use than just upload in youtube
Hope this helped 
