How to cut a movie in Windows Live Movie Maker?

Well, I'm trying to make a decent gaming channel based around minecraft. I want to do like an hour long recording but split it into 15 minute episodes or 20 minutes. How do I do this? This is kind of like what CaptainSparklez does along with my other gamers on youtube.

If you also know of any FREE video editing programs better than movie maker, please tell me.

Added (1). P.S. That shouldn't say 'my gamers' it should say many gamers xD

Honestly, I find Windows Movie Maker a quite underpowered video editor. I have tried using it once or twice but it doesn't produce the desired results.

You can use some free and open source other video editors like Lightworks, Avidemux, Kdenlive, VirtualDub and others. Some of these editors are track based and some are filter based but both of them will get your work done.

You can check this link for more details:
http://www.opensourcealternative.org/multimedia-audio/video-editors/open-source-alternative-to-premiere-pro/