[dragonwriter]

I really agree that the recommendation on aliasing is just plain wrong. I prefer using singular names relating to the role-in-the-query, e.g.:

  SELECT manager.last_name AS manager_name, 
         employee.last_name AS employee_name
    FROM staff as employee
    JOIN staff as manager
      ON employee.manager_id = manager.staff_id

This is probably most important (as in the above example) with self-joins, but I think its a good practice more generally, and makes queries more self-documenting as to intent.