Overall, the build process is well laid out. As you begin to build your ToM, can't overemphasize how important it is to familiarize yourself with each stage before starting anything. A couple of things that helped me :
I spent a huge amount of time searching for small parts. Not all the small envelopes are labelled, and it can get confusing. The first thing I would do if I were doing it again, would be to amalgamate all the common fasteners - eg all the 3mm hexnuts in one container, and all the 16 x 3mm capscrews in another container. In many cases, you may find yourself trying to locate a small part in among other different parts, and you can miss them, leading to longer times for each stage, and a raised level of frustration. So since you're going to look for things anyway, I'd go and get one of those large-size, transparent pill-containers they sell in pharmacies, or a set of small clear boxes, and separate and group things together. It will save you time, and reduce mistakes. There are a bunch of places where 12 x 3mm capscrews are used : separate them out, and put them in their own container; there are a bunch of different kits, with separate bags that contain 16 x 3mm capscrews; group them together. Get all the very small screws into a couple of containers.
The photos are pretty accurate, and the build stages are broken down, but I think the instructions would be improved by starting with a picture of a finished stage, and a diagram of how it fits into the larger scheme. It was hard to get a clear picture of the z-axis stuff, for instance, and an image of the finished item would be good at the beginning of the page. If nothing else, this makes it easier to quickly identify the page you're interested in.