You can access things like the record owner email address or owner manager name through formula field or workflow rule.
For example, if you need to get owner email address and it is not for queue, your formula would be Owner:User.Email, this formula field will return blank, if the object is available for Queue and record owned by a Queue.
From above sample, if the object supported by Queue, you can enhance the formula to:
IF( ISBLANK(Owner:User.Id), Owner:Queue.QueueEmail, Owner:User.Email )
To get User name or Queue name:
IF( ISBLANK(Owner:User.Id), Owner:Queue.Name, Owner:User.FirstName & " " & Owner:User.LastName )
User and Queue objects can be referenced on the Owner lookup, but must be explicitly selected, see screenshot below: