I’m working on a skill share powerpoint to share image stacking, how I learned it and how I do it. (For stuff I’ve already posted about this, see this post). This post will include additional references on image stacking, focusing on star trail style stacking and images by other photographers.
Astrophotography: Star Photo Stacking by PKM (instructable)
Photographer Lincoln Harrison captures jaw-dropping photographs of star trails. Shooting from the Australian outback, he spends up to 15 hours creating each image of the night sky. Shooting with a Nikon D7000, Nikon D3100, and a wide assortment of lenses, Harrison captures a large number of exposures of the foreground and stars separately. He then combines the images (sometimes hundreds of them) into amazing photographs showing the sky dominated by colorful star trails.
Further browsing Petapixel turned up photographer Ben Canales (see Zhang’s Petapixel article on him here) who also does stacks of stars. His website is here and a tutorial video he did about his workflow is here.
Example of Grant Kaye’s star trail photography can be found here.