Bought this with the game to help me discover everything as I play through, but was very disappointed with the guide.
It has good info about how-to-play, how to set up for stealth or combat styles, info on weapons/abilities etc. It has a combat and stealth walkthrough for each mission, though I found it could have used a more step-by-step process at some points.
It does not include where items can be found, not even big items like praxis kits or triangle codes, which was very disappointing. It does not say where there are side achievements that can be done at particular points in game playthrough.
I regret buying this. I am a completionist and bought the guide to help me discover all the locations/hidden passages etc, pick up the items, and work through the trophies/achievements. I found this guide useless for all of that, and had to go online to find missable trophies, important items included in walkthrough and so on. I didn't need the guide for how-to-play info, and found it easy enough to ignore the mission walkthroughs and play through it myself. It also had wrong information for conversation choices – if you are trying to get a particular outcome for some conversations, the guide gives you the wrong selections.
Overall, it has good basic how-to-play, and an average guide to missions. Very bad completionist walkthrough though. Would not recommend to buy.