its asking for your aol email address user name and password so it can authenticate..here are instructions if you have a BIS Acct and are a cingular wireless customer
New Users: Creating a new BlackBerry Internet Service account.
Existing Users: Logging into the BlackBerry Internet Service.
A valid username and password for the AOL accounts.
Users must disable Parental Controls on AOL for this to function properly.
Users must NOT be logged in to AOL at the time of set up.
Note: Up to 10 e-mail accounts can be integrated through the Blackberry Internet Service.
Integrating an AOL account:
Access the BlackBerry Internet Service at www.cingular.com/blackberrystart
Select "Customize your settings to receive messages from other email account".
Select Add Account.
Enter the appropriate email settings and select Submit.
User Name: user defined
Password: user defined
Re-enter Password: user defined
A checkmark on the account confirms it has been configured.
New e-mail will be sent to the RIM BlackBerry device and will also be available on the BlackBerry Internet Service account by clicking on Inbox.