Join Tables without losing Data
Use an outer join:

SELECT c.first_name, c.last_name, p.phone_number, p.extension, f.fax_number, e.email
FROM Contact c
LEFT OUTER JOIN Contact_Phone p ON c.ContactID = p.ContactID
LEFT OUTER JOIN Contact_Fax   f ON c.ContactID = f.ContactID
LEFT OUTER JOIN Contact_Email e ON c.ContactID = e.ContactID


Any missing information will show up as NULL.

This assumes that all contacts will at the very least have a master record in Contact.