[GNC] Setting up Gnucash for Household

[gnucash at notyourhomework.net]

I want to use gnucash for tracking income and spending for my wife and I. I'd like some rudimentary advice on setting up gnucash. 

Our bank allows us to set up sub-accounts, so we have ended up with four accounts: a cheque account which is used by both of us for day to day expenses; a "web saving" account which will attract a very small amount of interest when money is stored there; my wife has an account for her business use; and I also have an account for my business use. We transfer money between these accounts as required. 

It seems as though we should have separate gnucash file for each of these accounts. If so, how do we handle the transfers between them? If it isn't necessary to have separate files for each account, how do I set up?

thanks,

Malcolm