When I come home after having my home cleaned there is a fine sprinkling of dust on my darker wood furniture. Why?

This probably isn’t a problem with your maid service. The problem is with your filter on your air handler. There is at least one for every air unit in your home (1 to 3). They can either be found at the unit itself or as a large return vent on the wall or the ceiling. (Don't confuse it with your heating duct vents. The duct vents are smaller and designed to bring hot or cold air into a room. The return vents are typically two to three times the size of your duct vents.

Most filters should be replaced every one to three months, depending on make and quality. Make sure you don’t buy the cheapest filters that look like they have spun fiber glass as their filter mechanism. This type is basically worthless. Good filters have either a washable filter mechanism or a ribbed mechanism with a covering that can't be seen through. Good filters also have a rating that shows how long they are good for and how small a dust particle they stop. Point three microns is a good gauge – that’s 0.3 microns.