How do you personally prep each floor?

I'm doing DotMM as a first-time DM and I'm super excited! As far as prep goes, I'm a little bit nervous, and I really really really want my friends to enjoy what I'm bringing to them, and as a result I'm pretty sure I'm over-prepped for our session one. My level 1 prep has involved me taking the book and writing out, in fewer words and with highlighted key items/enemies, EVERY single room of level 1, along with sticky notes highlighting certain things that may happen or "if" conditions.

Yes, every single room. Every 41 of them. It was a lot of writing. It's almost probably certainly too much on my end, but I'm here to please and what's done is done.

However, I don't necessarily want to carry on with my over-preparing ways for the foreseeable future. How do you, personally, prepare for a new level of the dungeon? Should I just let go and read my room info straight from the book, only noting down any changes I'd like to make? Do you have a better approach? Me, and the callus I'm developing on the side of my pinkie, would appreciate it.