Shopping for a car seat may not be as much fun as picking out a crib and layette, but it's one of the most important products you'll choose as a new parent.

According to the American Academy of Pediatrics (www.aap.org), more children are killed and injured in car crashes than from any other type of injury (for a comprehensive car seat safety guide, go to AAP's Web site). If every parent used a properly installed car seat, traffic deaths of children four years old and younger would be reduced by half.

All seats must meet federal safety standards, but safety experts say that seats with five-point harness restraint systems are the safest. Many new models have built-in tethers for added security, but for others you may need to buy a tether kit separately and have a tether anchor installed in your car by the dealer.

Here are some tips to keep in mind when you're buying and installing a car seat.

• Basically, there are four car seat styles: rear-facing car seat/carriers for newborns to one-year; convertibles, which face the car's rear for babies to one year olds and then face forward for toddlers; front-facing seats for toddlers; and boosters for children who weight more than 40 pounds and are too heavy for conventional car seats. (Note: Children should ride in the rear-facing position until their first birthday or until they weigh at least 20 pounds.)
• Read your vehicle owner's manual carefully. Some vehicles, especially older models, may not safely accommodate a car seat in the rear, middle seat. If you don't have the owner's manual, call the manufacturer to request one.
• Install several different types of car seats in your car before you buy one. Follow the manufacturer's installation instructions exactly. You will discover that some fit more securely in your car than others. Be sure to use a locking clip if your car's seatbelt doesn't lock in place once the seat is installed.
• To securely install a car seat, use the full weight of your knee to press it down into the automobile's upholstery while tightening the seatbelt to the car seat or it's base. The car seat should be held firmly against the car's seat back. If you pull it forcefully, the seat should barely tip forward and backward or from side-to-side. If you can move it more than two inches in any direction, it's not adequately secured.
• Never use a car seat in the front seat of a car with a passenger side airbag. (Ideally, never use one in the front seat. The safest place is in the rear, middle seat.)
• Find out when there will be a car seat check near your home. Many hospitals, fire and police departments periodically sponsor these "drive-through" events during which an expert will check if your car seat is properly installed. Check www.safekids.org to learn about upcoming events in your area.
• For recalls or other safety concerns about your child's car seat, call the National Highway Traffic Safety Administration's Auto Safety Hotline at (800) 424-9393 or visit www.nhtsa.dot.gov.