You can create a Parallels account either on the Parallels website, or by using one of Parallels applications.
Creating an account on the Parallels website
To create a Parallels account, go to the My Account page on the Parallels website.
Switch to the Register tab, and enter your contact information.
To manage business products, like Parallels Desktop for Mac Business Edition, Parallels Remote Application Server, etc., check the I represent a company or an organization checkbox and enter your company information.
When you complete the registration form, click on Create Account.
Note that you can register using your Facebook or Google+ account.
Please check your email inbox to activate your account.
Once your account has been activated, you will be able to download a trial version of Parallels software, register your Parallels product licenses, and gain access to technical support.
Creating an account via a Parallels product interface
When you start some Parallels applications for the first time, you will see a sign in window. You will also have two options: to sign in to an existing account, or create a new one. Select the option to register a new account, fill in the contact information form, and proceed according to the on-screen instructions.