1. Import images and video clips
Just click the button "import images and videos" to import your files into Win Movie Maker project. Then you can use these files in your movie. Just drag selected files to the Timeline.
2. Select files and add to timeline
Select files and add them to Timeline. Then the files will be in your movie. Files already added into Timeline have blue checked mark on the bottom right. You can add checked files again of course.

3. Use sample color and sample videos come with software
There are some sample videos come with the software. You can insert the sample videos into Timeline. The sample videos will make your movie more sophisticated.