I would just use MS Movie Maker.
http://windows.microsoft.com/en-us/windows-live/movie-maker It does a nice job and is free and his laptop should run it just fine. He just needs to watch his processor temperature when he renders. Most laptops have descent power but don't do a good job dealing with the heat when you work the processor. HP laptops are particularly bad with heat. I like a free program call core temp to monitor processor temps. He can set it to show highest core temp, auto start with windows and have it automatically minimize to the task bar. Puts the temp next to the clock at the bottom of the screen.
Once he gets done with movie maker you can spend a couple hundred and get a copy of Adobe Premier. It is not easy to use but you can grunt your way though it. In the end, if he gets good with it he can get a job editing. Premier is a profession software package. My high school uses it to teach video editing. The same students also tend to end up on school tv doing the weekly news. So he may eventually end up on school tv.
Good luck to him. If he is brave, he could also start a video blog on Ytube. If he wants to end up in the entertainment industry this is a great way to start.
