There are a lot of blogs about SEO.
And I've read most of them.
But the best one focused around SEO and link building I've found is Backlinko.com by Brian Dean.
For a few reasons:
The articles are very thorough
The content is super actionable
It feature in depth research
Articles are well laid out and easy to read
It's always updated where required.
If you are at all interested in learning about link building and SEO, I can't recommend this blog enough.
(And if you've read it, do you agree? What other book would you recommend for beginners?)