I was wondering if there is a fake (or real) example of a site that is designed with perfect onsite SEO. I want to just see the site structure and how it is set up. I want something very basic that I can just click around to explore to see how it is clearly set up. Is there such a thing? If not -- maybe it would be a good idea.
Just take a look at some of the websites that rank well for competitive search terms, especially ones within your niche. Your website does not need perfect on-page optimization, but it should at least be as good as your competitors. There isn't just one right way of doing things though. There are many ways to jump through the search engines' hoops and give them what they want.
For an on-page SEO guide, saversites would benefit you a lot! Vansterdam is right, competitor analysis would be a great help for high SERP. Anyway, there are other factors that are relevant that will affect your site performance.