When most people think of home security, they think of monitored alarm systems. Alarm systems don’t have to be monitored and they don’t have to be a “budget buster.” There are too many options both for installation and monitoring to fit within the scope of this primer.
Unmonitored, wireless security systems can be had for as little as $100. These can be programmed to turn on your lights and trigger an audible alarm. These alarms serve primarily as an "early warning system". They prevent an intruder from entering your home unannounced. Some of them can dial outside numbers, to ask a neighbor to check on your house.
Monitored security systems can make sure the police are summoned, even if you are unable to use the phone. If you avoid the big name alarm companies, it is possible to get a monitored alarm system installed for under $500 and pay less than $10 per month for the monitoring service. Some of these systems monitor for fire or water, too.
Consider getting a dog. Dogs won’t provide effective and reliable protection, unless specifically trained for it, but they make a great early warning system, if you are willing to investigate when they bark. Smaller dogs often provide a better “bark alarm” than big dogs. Big dogs, however, prove a better deterrent to a potential burglar. Any dog will provide some deterrent to burglars. Do not get a dog with the intention of assuming it is a guard dog, unless you are willing to get a dog professionally trained to guard. Dogs should be considered an early warning system and potential deterrent. Beyond that, dogs should be treated as family. If you can’t commit to properly caring for a dog, don't get one.
In short, lock your doors, lock your windows, and do whatever you can to keep someone from getting into your home unannounced.