I wrote a concise developer focused on-page SEO guide (https://www.checkbot.io/guide/seo/ https://www.checkbot.io/guide/seo/) sourced mostly from things Google

I wrote a concise developer focused on-page SEO guide (https://www.checkbot.io/guide/seo/ https://www.checkbot.io/guide/seo/) sourced mostly from things Google says, as well as a Chrome extension that checks the page factors from the guide (https://www.checkbot.io/ https://www.checkbot.io/). You can test a site you run with the extension and follow the guide to fix any problems found, learning SEO on the way.