Salesforce Success site – aka the Community site: http://success.salesforce.com
Help-standard information that you can also access from within your instance and always the best place to start looking.
Learning Center -Lots of online tutorials and help here for free!
Lots of blogs, tools, cookbooks, and forums/assistance there too for items that are a bit too complicated (needs visual force/apex etc) to answer on Answers.
LinkedIn – Below are some groups to tap into for help – there are also many user groups who have groups on LinkedIn.
YouTube Training
Quizes
Facebook – Groups on facebook to look into joining.
Blog list – Great blogs to learn more about how others are using Salesforce.com Check out the link on the home page or some listed below:
Salesforce.com Channel – a resource to collect all the videos about salesforce available
Twitter! There are tons of people watching twitter who are happy to help a fellow user in need. I’m @eliz_beth
You’ll want to add these to start with: @salesforce @forcedotcom @getchatter @dreamforce @benioff
How could I forget Dreamforce
Trust site! Where to go to see the status of your instance. http://trust.salesforce.com
Force.com is an extremely powerful, scalable and secure cloud computing platform. Force.com enables ISVs to develop products up to five times faster, and at much lower costs as compared to traditional software platforms.