The most accurate way to estimate drywall panels is to plan each wall or ceiling plane in 4-foot increments. If you do this, note any vagaries in stud or joist spacing. Space screws 12 inches apart along walls and ceilings. You'll need 5.3 pounds of nails per 1000 sq. Don't forget the trim you'll need to finish new drywall.
Outside corners require a metal or plastic corner bead for protection.
You'll also need J-molding to cover exposed panel edges. Drywall Nails Lbs. Gallons Lightweight All Purpose Lbs. All Purpose Lbs. Powered Hot Mud Rolls of Drywall Tape 75 ft.