This will be handy: The folks at MOZ have released a new SEO Cheat Sheet updated for 2015.

Introducing the new and improved Web Developer’s SEO Cheat Sheet. Download info on SEO best practices for online marketers and developers. Updated for 2015.

Source: The Web Developer’s SEO Cheat Sheet 3.0 – Moz

Download: SEO Cheat Sheet for 2015