How do I keep the dust out of my house, or at least to a minimum?

We just bought our house this past summer. It's a brick house in a rural neighborhood.I have cleaned my house from top to bottom, but it seems like everyday, the dust on the furniture is built up again. And not just a little, it looks as if it hasnt been dusted in weeks! We have ceiling cable heat, so it's not dust due to dusty ductwork or anything. And, my husband or I neither one have dandruff or dry skin..So what is it? And what can I do?