Creating an account
To join, open the Sign up link in the top-right corner and choose a username, enter your email address, and pick a password. Your username is how other people find and mention you, so pick something you're happy to be known by.
The form also has room for a display name and a short bio, if you'd rather fill those in now - both are optional, and you can just as easily leave them and set them later by editing your profile. A display name is the friendlier name shown above your username on your posts and profile; leave it blank and your username is shown instead.
Once you've signed up you can read and post right away - unless this site verifies email addresses, in which case you'll need to do that first (see verifying your email). The very first account created on a brand-new site automatically becomes its administrator.