I have been teaching nightscape photography at Joshua Tree National Park for a number of years and everyone asks me about star trails and timelapse videos.
Once you know how to take a good single picture at night, taking additional pictures for star trails and a timelapse video is easy. Production can be as complicated as you want to make it, but the videos I've posted only take a few minutes each to create using a simple workflow and easy to use software. When I get time for my blog, explaining this process will be one of my first posts. In the mean time, send me an email if you have any questions.
Below is an example of what is really quite easy to do, with more on YouTube. There is also a little trick with this one. It is a new moon, so how did I get consistent light painting over 240 pictures?