Select a hierarchy level for the account from the Role list.
For Reseller or Site Owner roles, the Plan list is displayed. Select a plan which you want to assign to the new user.
Site owner account enables a user to manage their web site created in the Wizard.
Reseller account enables a user to do almost the same tasks as a Plesk Sitebuilder administrator, excluding some specific operations, such as upgrading and backing up Plesk Sitebuilder, setting up an SMTP server for sending notifications to the users, viewing logs, and the like.
If you indicate user as Administrator, the Plan list is not displayed, because administrator account is limited only by the Plesk Sitebuilder license.
If you want to proceed to registering a site for this account immediately after creating it, select the Proceed to registering a site for this user check box.