A Home Burglary occurs every 15 seconds according to the FBI. This does not mean that you have to be a victim. There are common sense things you can do to secure your home, and most of them do not cost a lot of money. Some are free.
First, always lock all windows and doors, even when you are home. Easter Sunday a year ago my neighbor was at church and her elderly mother was home in her bedroom. A miscreant walked up their driveway, opened the kitchen door and walked right in. Fortunately we are vigilant in my neighborhood and another neighbor just happened to be washing his truck down the street and witnessed what could have turned into a tragedy.
If your doors do not have deadbolts - get them. A proper deadbolt will be keyed on both sides if your door has a window. The bolt should have a one inch throw, and strike plate should have three-inch screws. Your outside doors should be solid wood core, or steel.Other than replacing a door, the rest is a relatively minor upgrade.
Your windows should have stops, and secondary blocking devices as latches do not act as a secure deterrent to forced entry. Something as simple as a cut broom handle to prevent a closed window from being lifted works wonders.
Lighting - criminals do not like to be seen. Install motion detect lights - high enough to be out of reach of the nefarious minded - around the perimeter of your home. Install light timers in key rooms in your house.
Remove hedges and bushes that could provide cover, especially if they are in front of windows or your porch.
Alarm systems can be effective as a deterrent - but they are only as good as the other precautions you take to secure your property. They work as a deterrent only because some intruders fear being caught. However, better than a security system, get a dog.
Dogs provide companionship, are cheaper to maintain than a security system, and are mobile. We have three dogs, and all of them bark when someone approaches the house. Dogs do not have to be vicious to be an effective deterrent. And best of all, a secutiry system does not keep your feet warm in bed at night!