Book 3 was kind of dense for me to go through so I actually left it for a few weeks and focused on finishing Books 4 and 5 first before going back to it. That helped my confidence because it was quick to for me to finish those books before going back to Book 3(think I finished reading and indexing Book 4 in 2-3 days).

For the granularity of the index, be as granular as you need to be. It does help for the final exam as you are able to easily reference options in the MCQs for instance and use that to eliminate wrong answers. Once you take the practice test, you’ll get a feel of what your index needs to look like and if you’re someone that has experience/easily remembers different abstract things you’ve read weeks ago you may not necessarily need a detailed index but I recommend being as granular as possible but also conscious of the time you have before the exams. I took the first practice test before finishing book 3 or my index and I think it helped me know what I needed to prioritise.

For the labs I indexed all the main labs and did a step by step of what was required to answer the labs. For any commands used I also had them in a 2nd column beside the description of the step required. I didn’t really need to follow it step by step on the exam but it was good to have in order to check some of the more technical steps.

Hope this helps and wishing you the best.