If you would like to make a how-to video, Animoto has blogged about it. Here are the general steps:
Choose a topic for your video. Make sure it's something easier shown in a video than using another medium.
Use a title that accurately describes your video and makes viewers curious.
Give simple instructions that viewers can easily follow along.
Add a lot of video clips or photos that show how and what to do.
Edit fiercely to make sure the video is less than 60 seconds, or you risk loosing many viewers before it's over.
Read the whole blog post at Animoto (why didn't they make a how-to video instead?):