Most RPGs make you ask the ask the same question: what was that giant rat doing with a sack of gold coins? Fable II has gone the more realistic route: you'll have to work for your money. There are some mini-games that simulate trades like blacksmithing, but one of the options is to invest.
Presumably you'll be able to rent out homes just as you did in the original Fable, but in the sequel you can invest in shops. Luckily they're not going the truly realistic route: you won't have to stop by the shop to pick up your profits, nor will you have to break someone's thumbs if they can't pay. As you're off slaying Hobbes or robbing innocent merchants, the cash will roll in every five minutes of real world time.
If you find yourself unable to play for a while there's an odd side benefit: the cash will keep rolling in even when you're not venturing through the world of Albion. Even when your Xbox is turned off, you'll accumulate the same amount of profit every five minutes.