Keeping fleas out of the house will be the natural result of keeping them off your pet and keeping them out of the yard. Aside from that, all you really need to do is be vigilant about vacuuming. There is really no reason to treat a problem that doesn't exist so luckily all you really need to do is keep your eyes peeled for signs of infestation.
I have heard of people having their foundations sprayed and so on but I can't imagine that it is very effective because most fleas will be tracked in from the yard on people & pets anyway. It might get a few but spraying toxins all over the place can't be good for you and it just isn't necesssary for fleas. (Exterminators will tell you othwerwise of course.)
If you have fleas in the house, however, you will need to visit the flea extermination page and get busy.