I am looking for the name of someone in the worcester, ma area who installs drapes and rods purchased retail. Who might also hang artwork as well.
I think you'd better look for a handiman. No one who sells drapery is going to come out to hand curtain rods if you haven't bought your supplies from them.
Pictures are hung with the center of the painting at eye level. Gallery height is 60 inches from the floor. If the people viewing them are tall then hang the higher--if shorter hang them lower. For grouping pictures first lay them out on the floor and arrange in an atractive group. Then determine how high you want them. With a soft washable pencil draw a faint line on the wall where the tops go. Then hang and wash off the line or erase with a gum eraser.
I would try calling a fabric or sewing supplies wholesaler in your area, they may know someone who installs freelance, a lot of drapery installers are independant and go where the work is.
Or try craigslist, but check references!