JayCut. This is the site I used to make the video of Nolan in his crib, a few posts ago. I have used Windows Movie Maker to do the same kind of thing in the past, but that program has always been touchy and problematic for me. JayCut is online, so it automatically saves your work if you forget (like I do). It is also very useful when sharing videos to different sources: Web, PC, or Mobile. You just need to upload the video and then you can chop it up, edit it, and create a great looking video.
Below is an image of what it looks like when using the JayCut editing program online. It is extremely easy to use, clear, and great for beginners.
I would definitely recommend my students using it for any school projects they might be putting together. An example of one video I made very quickly, only in about 30 minutes is below. I could have even added text or put music to it, but I decided to keep it simple. Check it out at jaycut.com and have fun with it!