I'm in no way saying this recipe is superb, but it was one of my first extract recipes I formulated myself and it turned out pretty well. I'm sure a more experienced extract brewer could help you out more. I switched to all-grain long ago and seem to have forgotten about most of the extract process.
Obviously this should be made as a partial mash, but when I made the recipe, I steeped the grains at 152 and it turned out fine.
5 lbs. Dry Dark Extract
.5 lbs. American Chocolate Malt
.5 lbs. American Black Patent
.25 lbs. Black Roasted Barley
.75 lbs. Lactose
.75 oz. East Kent Goldings (Pellets, 4.5 %AA) boiled 60 min
.75 oz. East Kent Goldings (Pellets, 4.5 %AA) boiled 10 min