Every resource you can possibly imagine for SEO, and online marketing is neatly compiled in this amazing Google Doc from Annie Cushing.
It Covers everything from SEO analysis, to social media marketing, to data sources for content, to infographic submission sites, etc…
This doc is worth millions in the right hands…Makes me wish I had two right hands.
Seriously, make a copy of it in your Google Drive account, and whenever you need to do something online, just reference it and you will have all the resources you need, neatly compiled by its function, if its free or paid, and an easy to click link.
This Spreadsheet is arguably the most valuable resource floating around the SEO community.