The success or otherwise of your website will largely be determined by Google and the extent to which your site conforms with their guidelines. It follows that understanding the rules of engagement should be very high on your webmaster or website developers to-do list and tick off as many boxes as possible.
Google Quality Rating Guidelines were updated in March 2016. These are the same guidelines Google provides to the people they engage as evaluators to review websites and their content.
The guidelines provide interesting reading and worth making the time to, all 146 pages of it which can be can be downloaded here.
In the simplest of terms, the key theme that defines these guidelines is expressed as E-A-T or expertise, authority and trust, and is central to Google’s intention to deliver the best possible user experience.
There are estimated to be more than 200 factors that Google reviews when determining how well a website and its pages rank. Of these, 36 factors can be readily applied to all websites and can be reviewed by analytics and SEO audits to ensure they exist and just how effective these measures are.
See Bruce Clay Inc SEO Checklist that provides a comprehensive SEO Checklist of 36 factors that should be installed and maintained on your site.
Key factors to being Google friendly
Accelerated Mobile Pages (AMP)
Site Navigation using Text
Meta Tags including title, description and keywords
Structured Data Markup using Schema Markup
Social Meta Tags
Content Architecture (Theming and Siloing)
Static Home Page Content
Content Uniqueness and Freshness
Content headings (h1,h2, h3 for headings, subheadings etc)
Image and Video Optimisation
Site Speed and Performance
Third Party endorsement
Quality Backlinks from other websites
This is by no means a complete list but an initial must have on all websites.