One of the best ways to control a spider infestation is by eliminating other bugs in and around your home, which is what spiders feed on. You can also control spider infestations by keeping both the inside and outside of your home clean so that spiders will have few places in which to hide. It's also typically considered a good idea to seal any cracks in windows or doors that spiders may be slipping into. Getting rid of spiders already established inside your home will probably involve the use of insecticidal sprays, bug traps, or possibly an exterminator if the problem is out of control.
Spiders feed on other bugs, and it's possible that spiders are problematic in and around your home because of the presence of other bugs. If you get rid of other bugs hanging out around your house, your spider infestation should diminish because their food supply will be either greatly reduced or completely eliminated depending on what measures you take. Keeping a light on outside your house at night tends to draw spiders because other bugs are attracted to light, so you could make an effort to keep your outside lights off at night. If you have a problem with gnats, flies, or roaches inside your house, take the appropriate measures to get rid of these bugs, and you'll probably notice that your spiders are disappearing as well.
Most spiders like to hide inside of dark nooks and crannies both inside and outside your home. Keeping your home tidy and free of lots of clutter will cut down on the hiding places spiders have. You should also notice whether you have piles of wood, debris, or lots of bushes right next to the outside of your house. Spots like these are ideal for harboring spiders, and you might be able to take steps in eliminating your spider infestation if you get rid of debris and excess greenery that is either touching or very close to the outside of your home. It would likely also help to spray an insecticide that is labeled as being effective against spiders around dark corners inside your home and around the perimeter of the outside of your home.
Even if you successfully eliminate a spider infestation, you are at risk of future infestations if you don't attempt to find out how spiders are getting inside your home and seal these places up. You should check for large cracks under your windows, doors, and in your foundation for places large enough for spiders to enter. Filling these cracks up with caulk or using some type of weather-sealing materials should prevent the vast majority of spiders from being able to get inside your house.