Step 1, import videos. You can click the Plus button, select “Import/Add video”. Or use the shortcut Ctrl+1. Or just drag the videos into YouTube Movie Maker.
Step 2, drag your videos to the video line or overlay line.
Step 3, video editing. Right-click on the video to edit, you can Cut(Alt+C), Crop(Alt+P), Split(Alt+X), Rotate(Alt + R), etc. You can see all the YouTube Movie Maker Keyboard Shortcuts here.
