Whether you design, develop, or just use WordPress, or perhaps all three, you will run into questions. Some people know WordPress like the back of their hand. Others have cheat sheets or their own theme frameworks. However, the first place to start looking is the WordPress Codex.
The WordPress Codex is a wiki for people to learn how to use, design, and develop with WordPress. It is free to use and free to edit. Many questions that people ask can be found in the Codex first. Of course, not everything is in the WordPress Codex, but many of the basics are. I have found myself referencing links to the WordPress Codex when answering questions many times.
As mentioned, the wiki can be edited, but it is monitored, so you cannot spam it. Any links MUST be original and informative, and code syntax shared must be correct.
How often do you look at the WordPress Codex? Have you contributed to it?