Is selling the children bad?
My house is pretty well setup; transport wise and shopping wise (can easily walk to both train and supermarket). The car would probably be first to go. I really don't have too many other possessions that would fetch much, though we are going to be offloading baby things soon - have a decent 3 wheeled jogger pram that will probably sell well, though without a car this might actually get more use!
I have lots of books, but I don't think they have a great re-sale value, but might be a place to start.
Last? I think the house would be the last to go and I'd have to be pretty desperate to do it.