Roof Installation???

how much does it cost in labor for roof shingle installation?? Its a normal pitch roof...

$2.00 a square foot
its not just shingles you are installing along with putting the shingles on you have to install a base sheet of felt flashing around the perimeter(drip edge),flashing of air vents and vent pipes but before you start putting the roof on unless your starting with a new wood deck ,you have to remove at least the first 3 rows of shingles around the perimeter of the roof.by doing this it ensures your starting shingles run straight and true ,but it also leaves a cleaner line at the edge of the house cause you cant see 2 or 3 previous roofs at the edge .$100.00 to $150.00 per square is a good price .depending on?1 SQUARE is equal to a 10 foot X 10 foot square.it is also the term they use when ordering roofing material so if the area of roof you where replacing measured 2000 square feet that equals 20 squares of roofing material.