I found a few references that might be useful to you. The first two are in PDF format, so they’ll possibly ask you to download them. They belong to Google, so I’ll presume they’re clean.
Website Grader from Hubspot. This tool is a really great way of seeing how you stand with typical SEO and social engagement scoring. Start here.
Google Search Engine Optimization Starter Guide (pdf). You can use this to understand the basics behind the scenes on how search engines like Google see your website or blog.
Google’s SEO Report Card (pdf) – Useful for knowing what Google sees when they look at your site. A lot of what’s covered in here is measured by the Website Grader tool mentioned above.
WordPress SEO. If you’re using WordPress for your website or blog, this is a really useful resource. It’ll take a while to pore through, but you’ll find some value in it, for sure. My friend, Yoast, also has a WordPress SEO plugin that you might find useful.
I also use Scribe (affiliate link) to help me with my SEO on this site.
Hopefully this is helpful to you.