According to CCTVConsult.com, there are a few features you should consider before purchasing a closed-circuit television system. A hard-wired system can offer greater range than a wireless system, but a wireless system can be discreetly hidden in areas where cables might give the camera away.
If the cameras will be in low-light situations, consider black-and-white images over color. Color images are clearer, but black and white works better in dark areas.
You will also need to consider the area you will want the cameras to cover. Anything more than a 78-degree angle will give blurry images. If you are looking for clear images, then a good angle is around 70 degrees. That means you might need more cameras to cover the areas you want to monitor, but the images you see will be easier to decipher.
The kind of monitoring you need will determine what kind of equipment you will purchase. If you want to place cameras outdoors, get equipment rated for outdoor use. If you are looking to keep an eye on just one room in the house, then Servicemagic.com suggests a small wireless Internet camera. It will require regular maintenance such as changing batteries, but if you are trying to do covert surveillance it might be more appropriate than a hard-wired camera. If you want to keep track of nighttime activity, you will want to invest in a system that offers night vision to allow clearer images in the dark.
Many home surveillance video systems can do digital recording. You can choose to have your recording done directly to a computer hard drive, or you can use a digital video recorder system that captures and stores the video for later use. A computer hard drive might be more convenient because you can easily transfer your video to DVD for archiving purposes. If you do not need to archive your video, then a DVR system is a good choice because it can be hooked up directly to a television for easier monitoring.