ffmpeg is another free option. It has a lot of options for converting to different formats and sizes, creating clips, combining clips, etc. However, it is a command line tool, and does take some reading over the help file to pick out which options you want to use. So I don't know if that still falls within your definition of "easy". A program with a GUI is probably easier to start using right away. And a command line tool might be a bit more manual work, but the overall process is simple once you get a workflow going.