You can import Contacts from Outlook. Outlook should be open prior to importing Contacts. This is not required but speed will be improved.
There are filters in the ribbon for showing All, New, or Matched Contacts. The New filter shows only Contacts who don't already exist in SI. The Matched filter will shows only Contacts that already exist in SI, use this for updating information for existing Contacts. There are column filters and a search field as well. You can also choose a specific Contact Folder from Outlook.
Select an available Address Type from Outlook to import as the Billing and Site Address: