The first thing you will need to do to use Amazon Web Services is sign up for an account. Go to http://aws.amazon.com/ and click on the Sign Up Now button. If you already have an account with Amazon.com and want to associate your AWS activity with that account, you can simply log in with those credentials. If you prefer, you can create a new account just for your AWS activity.
Make sure your account has been enabled for at least the EC2 service and the S3 service. The tutorial linked to above provides detailed instructions on signing up for services.
Once your account has been created, a variety of credentials will be associated with it:
These are the credentials you use to log into the AWS web portal and the AWS Management Console and consist of an email address and a password. Since these credentials control access to all of the other credentials discussed below, it is very important to choose a strong password for this account and to age the password aggressively.
This is the unique 12-digit number associated with your AWS account. Unlike the other credentials we will discuss, this one is not a secret. The easiest way to find your account number is to look in the upper-right corner of the web page after you have logged into the AWS portal. You should see something like Figure 1-2 ...