just go to the AOL Mail website and click on the "Sign Up" link. You'll need to provide some basic information, like your name and address, and choose a username and password for your account. Once you've completed the sign-up process, you can start sending and receiving email right away.
If you already have an AOL account, you can use that same username and password to log in to your AOL Mail account. Just go to the AOL Mail website and enter your username and password in the "Sign In" form. Once you're logged in, you'll have full access to all of your AOL Mail features.