business on shabbat

Question

I sell stationery I was offered to sell stationery at a boutique at a non jewish club. 15% of my gross sales goes to the organization. All I am doing is writing up orders nothing is actually being given to the customer that day - all orders will be faxed in the following week. This boutique falls on a friday, sat. and sun. How do I handle shabbat. Can they have someone there placing my orders, Can I pay a goy to work for me and write up the orders. What is permissible. They were aware of my being an orthodox jew when I met with them and they had suggested placing someone there from their organization to take orders. THanks!