Google Webmaster Guidelines and SEO Practice?

[Dev "D"]

I have heard that SEO is the basic grammar for a successful website. If it is really so what do suggest about this information available at webmaster facts -

http://webmasterfacts.com/google-webmast...lines-seo/

Again, I would also like to know if the information provided here is true or false? This is one of many websites that one can find about webmaster guidelines... But the information shared here seems to be too simple. Is SEO that simple to understand? I need an answer that is actual fact and not some hypothetical theory or suggestions which contains "May be", "if/else" or "Best practice" and other such practically impossible to prove phrases and sentences.