I went to Lynda.com and took the beginner iMovie `11 Essential Training. The duration of the training is 03:28:00. The way that the exercise files are organized made the time pass rather quickly. I was able to view the entire course over the course of two evenings. The author, Garrick Chow was excellent. He gave clear and precise instructions.
Garrick covered everything from making sure you had the latest version of iMovie, how to import video from whatever source you used, all the way to how to finalize your project once it is completed. I was able to discover easier ways to manipulate, organize, and how to edit the video clips. He provided the same video files that he used in the exercises so that there is an opportunity to work along with him. He didn’t leave anything out, except perhaps how to add voice / audio to the movie trailers. Overall, I give it two thumbs up!