For instructions on accessing voicemail and changing settings visit the ITS knowledge base article.
Articles of Note:
Single Inbox: Check Your Voicemail Messages Using Outlook Online (Office 365)
How to Modify Notification Preferences
Verifying or Changing the Ownership of a Voicemail or VoIP Telephone
For instructions on forwarding calls to a personal cell phone or land line visit Telephony - How to forward your phone calls.