IMHO, you will do much better selling it as a generator head (assuming it is in good condition without damage, of course) than you will do selling as scrap. To scrap it, you'd have to cut out all the windings from the iron because if you don't they will only pay mixed metal price for it, and mixed is going to be lower than virtually any other metal price.
I'd suggest Craig's List (CL), eBay or a SteelSoldier's classified advertisement.
As for shipping, weigh it, and go from there. For CL and eBay, you can specify pickup or buyer arranges shipping. For SteelSoldier's I think you should be able to do the same. If it is under (IIRC) 150 lb, you can ship FedEx ground easily. You will pay an overweight surcharge but that's not so bad. I've shipped heavy stuff in the past using my FedEx account and had no problems to speak of. Of course, you can ship motor freight too, just strap or bolt it firmly to a small pallet, or put in a wood box, and you'll be good.