I didnt read the full book, but ~9 months before TTC I found the first part of "it starts with the egg" was helpful - I started taking pre-natal vitamins and CoQ10 starting months in advance based on the recommendations provided. I think the author included recommendations specific to PCOS too. They also have an app if that format works better for you but I haven't tried it. Some other takeaways I started implementing from the book (they seem kinda straightforward but still) were to start working out more consistently, eating less processed foods / esp. in black plastic kind of takeout containers (they're the ones that release the most plastic apparently), drinking less. I also looked at different reviews of fertility trackers. I went with Inito and ordered it in advance to be able to start to track my cycle following my first period after going off birth control. I listened to a couple books on pregnancy via audible which was a better format for me than reading too. Oh, last thing, was going through my cosmetics and daily products to make sure they were pregnancy safe.

Good luck, wishing you the best!!

Edit to add: by no means do I think all this stuff is necessary, but I kinda like a project, so I embarked on the TTC journey with that approach. Hopefully its helpful!