Editing in schools is extremely challenging. Unless you have experience of editing and know that the available technology in your school has the power and memory to process video, it is better to leave it to an expert.
Most of the PC’s that I encounter in schools cannot process DV quality video. They may be able to handle lower quality video shot on a phone or digital camera but you will usually need to convert the files. You will need to test the whole process first.
For teaching editing, you will need a computer suite, with at least one PC for every two children but preferably 1:1. Moviemaker is the best software for the first step.
All PCs have a version of Microsoft Moviemaker. This is an adequate video editor for a beginner but it only works comfortably with the Microsoft video format – .wmv – files. No cameras shoot .wmv files they will have to be converted. So already it is getting tricky!
For the reasons listed above, I will not go into further detail concerning editing. Here are some links if you are interested: