Promptbooks are copies of the script with a whole bunch of handwritten notes inside that the actors would have used to detail exactly how a scene would be played. This site has scans of a number of Shakespearean prompt books, including Macbeth. Fascinating stuff. It’s a little hard to navigate at first. Head for the images, basically. If you find yourself on a page that says “Hand” a lot, it’s actually describing in detail who wrote what on the page — but there’s probably an image of the page that you can click on.