Facebook
Shout Me Loud: List of Facebook shortcuts and workarounds
Basic video to begin (uses page view before most recent design update, so it looks a bit old)
Privacy settings review; more info on privacy settings
CNN on Facebook's most recent changes
All Facebook: Facebook Bible
LinkedIn
100 Smart Ways to use LinkedIn
LinkedIn groups, and how to find the right groups to join
Tips for participating in groups
Twitter
Explained by About.com
Video by Common Craft
Another explanation by Pistachio Consulting
Top Twitter users (and who will follow you back)
Who to follow by topic
StumbleUpon
Tutorial to begin
As explained by Social Media Examiner
Pinterest
QR codes
Video explaining how QR codes work
Google as resource
Google+
Some very informative videos to explain "sparks," "circles," "hangouts," "huddles" and other terms unique to Google+
Another video take on Google+, comparing specifically to Facebook and Twitter
Google Reader
(other options for RSS readers)
Google Alerts
Searching Google: from the ordinary to the obscure
Google Related: new way to find related content
Social media for business purposes
Social Media Examiner: Getting started. Covers Facebook, LinkedIn, Google+, Twitter and blogging
Using Facebook to promote your brand: a great infographic
From American Express small business: Facebook's social plug-ins for your business; 5 Twitter truths
General technology information
Make Use Of (especially guides and cheat sheets)
Shout Me Loud
Mashable
Glossary of online/web terminology