Cloth ground sheets on the floor. As for the furniture, providing you are careful with them, Ummmm, the plastic throwaway dust covers are cheaper and will suffice.
I'd buy those cheap chuck away dust sheets too. You might want to consider taping them down though because they are a bit floaty and a draught can easily blow them off without you noticing.
The sofas will be wrapped in plastic. I would leave that on and get extra plastic sheets to put over that. In the same circumstances that's what we did.
You can buy plastic sheeting on a roll from decorators merchants. You can also get plastic backed cotton dust sheets from the same place.
Beware of cheap cotton sheets, as the paint can go straight through them.