Your not going to get a good video editor for free, so the best for you would be windows movie maker, considering you're a beginner. If you decider later on that you want something better, it would be best to just purchase a video editor. You can get Adobe Premiere elements for around $50-70. I'm not sure, mine came with my photoshop elements 9.

WMM....

Usally on a Computer there is a FREE video editting program that comes with it. For me it is Windows Live Movie Maker. If your computer is older or does not have Windows 2011 it will not have the up-to-date Windows Movie Maker. You can update your computer with Windows 2011 from the Windows website. Just search it on google and there should be a free download of Windows 2011 there which will update all programs that may need to updated. Other then this I have no other programs I could offer that I know of which are free. I used Windows Live Movie Maker for some videos before and I personally think it is wonderful for a free program which is automatically installed on your computer once the computer is purchased. I know of many great Video Editting people who use this program and also find it very useful, but it is up to you. If you have already tried it, then I am no use to you, but other then that, I know of no other free video editting program.