Most important books about webspeed.
More listed on Yeahub.
The WP Speed Matters blog is also a great resource, which can be found here: https://wpspeedmatters.com. With regards to plugins, the ones I use most are W3 Total Cache, Asset CleanUp Pro, ShortPixel AI, Flying Pages. I might also experiment with Flying Scripts. I will be serving HTML through Cloudflare and static assets through BunnyCDN