I am growing blueberries in N. Illinois, so we have similiar conditions, but your soil depends on where you are. Ask locally or get it tested.
Blueberries need full sun, and to be kept moist. You want loose, well draining soil that is fertile. Ground up pine bark works well. pH needs to be on the acid side around 4.5. Mulching with pine needles will help, as using Miracle Grow Fertilizer for Acid loving plants will (blue package, but realize it is NOT organic.)
As to how large they will grow depends on what kind you have. High bush is what I got from Stark Bros., but there are also low bush and now midhigh. (Rabbit eyes are for southern gardeners.) According to Rodale's Fruits and Berries book, Low bush need to be 2 feet apart and brow 12" - 18" high. Mids grow 18" - 3' high and need to be spaced 2' - 3' apart. Highbush grown 6' - 12' tall and need to be 6' apart. They are self polinating, but produce larger crops if grown with at least one other cultivar.
One other note on planting on a hill...avoid low lying areas which are prone to frost and poor air circulation. They don't require a lot of nutrients but could use fresh compost each spring. Good Luck!