I agree with Kipper on the books by C.W.Ammen.I have 4.Casting Aluminum,Casting Brass,The Complete Handbook of Sand Casting,and Constructing and using wood patterns.All very good books.He does focus a lot on the buisiness of casting.Running foundries was his trade.I assume you are like most of us,just wanting to cast parts for yourself.I learned a lot from searching the net.You might keep an eye on E-Bay for a crucible furnace and run into a deal like I found.A Johnson Gas Appliance crucible furnace for $250.$30 worth of refractory,a few cans of high temp paint,a 500k potentiometer for the blower control,and 3 days of work.It looks and runs like new.
Warning!!!!! You pour your first casting and you are a metal melting junkie for life.
Sorry for the long post.