There are dozens of brands of security cameras and security camera systems.  The internet has every kind of commentary about which cameras and systems are the best, or most cost effective.  I have a security camera system at my home.  If you don't have any security cameras, you can exeriment with a single camera purchase in a way that adds some daily value.

One brand of wireless camera goes on sale reguraly for $60-$70.  It's the Foscam FI8910.  It comes in black or white.  If you have a wireless network in your home, then all you need is access to power.  The FI8910 can rotate and pan with the use of a smarthphone app you install  It also comes with instructions to allow for remote access to your wireless netwrok and therefore your Foscam camera.

Once installed, it will provide live video of your home.  But it can also do two other things.  I have one of these camera mounted at my front porch.  The camera has a setting in its software that takes pictures when detecting motion.  It can then email these pictures to you.  So this camera can alert me when Fedex or UPS has left a package at my front door.  Or when my kids get off the bus and come to the door.  Also, if I'm meeting a customer in another part of town, and wonder if my lawn is getting any of the rain in the area, I can jump on the smartphone app and turn the camera away from the door and towards the driveway.  The camera has a microphone as well to pick up the sound of rain, or even thunder if you want to know if ther weather is severe.