Thank you for your help. Almost there I think.

Ok, so I create a class for each account/ fund, and subclasses as appropriate. Got it.

Now how does the "Item List" fit into this? When I record a donation, I assign it to the proper account (class), and then I have to give it an Item. These look like they can be assigned a separate account, so then I could register a donation to the "Operating" class, and assign it an "Missions" item which points to the "Missions" account. Which account would this donation register under? Wouldn't there be a conflict then?