After you have logged in, you can click on your User name to manage your profile; one of the features in your profile manager is the ability to Managing Your Subscriptions.
(image provided courtesy of America's Own Who's Who Inc.)
Step 1: Manage Services
The first step in managing your subscriptions is to click on the Manage Services link. This will show you all available services you can subscribe to, including any publicly available fee based services.
Step 2: Subscribing To a Service
In order to subscribe to a service, simply click on the Subscribe link next to the service name. Some services require a fee, which may be one time or recurring (such as in the example, above, which repeats every 2 years). Also note that some subscriptions require an RSVP code, which will be emailed to you by the portal owner to approve your subscription.
Step 3: Unsubscribing
To unsubscribe from a service, simple click the Unsubscribe link next to the service name.