Determine the best placement for attic ladder installation
The stairs should gain access to the attic in such a way that: 

1) one has max. headroom, 

2) the attic stairwell doesn't prevent access to any part of the attic, 

3) the stairs permits a path of travel to a ground floor exterior door (ie. doesn't come down into the hallway in such a way one would have to close the stairs to exit the bldg.)

4) the stairs would not likely require furniture to be moved to be used.