Since I wanted it to be a surprise for them I can now post some photos of the guest room, because I don't think they will be on internet again before they get here.
This is our guest room:
It has a nice and comfy bed, with lots of different pillows; a rocking chair with a reading light and a desk for those who bring their laptops or other gadgets. Adapters are provided if your plugs are different to ours (FYI we have UK plugs here).
The curtains will darken the room completely if you arrive in the middle of the night, or if you need to catch up on some sleep after a long flight. There is a lot of different reading material, both novels and information about the region, in your bed head.
Have I sold it well enough? Friends, do come and see us, we love to have guests! :)