The Salesforce success community is a great way to find information on a variety of subjects, ask and answer questions, and more. This site is definitely worth exploring. Side note: one of the best ways you can learn Salesforce is by answering questions that others have. I learned a ton simply by answering questions on the community site when I first started working with Salesforce.

A developer edition account is recommended as you can retain control over this account.  If you are using a corporate account to access the community site and then change employers, you will likely lose access to your old profile (community posts, Chatter feeds, Trailhead badges, etc.).