Most of the stuff you see online with regards to natural bodybuilding focuses on training and nutrition. Everyone agrees sleep is an important aspect of getting the best results possible yet there really is not a lot of information on this. My guess is that it seems pretty straight forward and there is not a lot of money to be made in promoting sleep. Here is a video by Omar Isuf discussing how important sleep is.
Omar references Greg Nuckols’s article on sleep which you can read here.
I also recently came across an online resource that covers everything you could possibly want to know about sleep. I consider these guys to be the equivalent of examine.com for supplements except for sleep.
Tuck Sleep is a non-commercial community devoted to improving sleep hygiene, health and wellness through the creation and dissemination of comprehensive, unbiased, free web-based resources. Tuck has been referenced by Well + Good, Smithsonian Magazine, Shape, Harvard University and by many sleep organizations across the web.
A few of their articles you might benefit from reading are linked below and they are continuing to add more over time.