To schedule an event with a contact in the corporate directory, perform the following steps:
Search the contact from the corporate directory.
See How Do I Search for Contacts in the Corporate Directory?
To schedule the event with multiple contacts, select the contacts using the steps described in the section What Actions Can I Perform on Multiple Contacts From My Address Book?
Right-click the selection and select Invite To a New Event... from the drop-down list.
A New Event tab is created with the contact added to the invitation list.
For more details about how to create a new event, see How Do I Create an Event?
Specify other attributes for the event and click Save.