Official Google Webmaster Blog – A great blog to follow if you would like to keep up with what Google has to say to webmasters.
Google Webmaster Support – Google’s help section on web design, SEO, outreach and other Google SEO related topics
Straight from Google – Quotes and information regarding SEO straight from Google, Inc.
Bing Webmasters Page - Search engine optimization best practices to rank on Bing’s search engine.
Google Videos – Google’s YouTube channel with a plethora of videos by Google and its employees.
Google Update History – Full list of confirmed Google algorithm updates since 2007
MozCast – Search engine ranking pages weather report. See ranking fluctuations day by day.
Moz Whiteboard Friday – Weekly informational videos on SEO and other internet marketing best practices.
Moz’s The Beginners Guide to SEO - A nice guide to search engine optimization for beginners
Google’s Official SEO Starter Guide - (PDF) Google’s official SEO guide for better rankings on their search engine.
Search Engine Watch – Probably the kings of search engine optimization news and tips.
Google Search Engine Paper – The Anatomy of a Large-Scale Hypertextual Web Search Engine
Moz Top Ranking Factors – Moz’s infamous search engine rankings factor page (v2013)
Link Value Factors – Very similar to Moz’s ranking factors, but focused on backlinks and link building.
Local Search Ranking Factors – Another ranking factors page, but focused on Local SEO and Google+ Places/Maps
Link Building Guide – The definitive guide to all things link building
SEO Checklist – A SEO checklist you can actually use when optimizing your website (updated 2013).
Search Marketing Infographics – All of the net’s best SEO related infographics and images.
200+ Best Social Media Resources – Find free e-books, tips, tools and more to master social media marketing and networking.
Local Business Directories List
Organic SEO Vs. Sponsored Listings
Link Building Tools
Top SEO Ranking Factors