Check the tread.  It's a good Idea to do this each season.  You don't want worn treads in the winter time or bald tires when you're getting ready for a big trip.  A simple way to tell is with the "penny test". Place a penny between one of the treads with Lincoln's head facing down.  If Lincoln's head is covered your good to go. If Lincoln's head is visible it might be time to get some new tires.

Why should I rotate my tires? Tires can wear differently from front to back from one side to the other. We don't always thing about it but every day habits and individual commutes can cause more wear on one side or another.  If you have a driveway and always turn left out of your driveway for your daily commute to work, the outside of your left front tire might wear more than the right back tire. In a front wheel drive vehicle, the front wheels do the turning so they will wear in different places than the back tires that are just going along for the ride.

Why is tire alignment important?  There's a lot of things that can throw an alignment off. A bad road, running over a curb, hitting a speed bump too fast, a suspension part going bad, etc.  This can throw the alignment off causing your car to "pull" one way or another. This can also cause more wear on certain tires. Poor tire alignment can actually reduce gas mileage too.  Poor tire alignment can also be a sign

Why does tire pressure matter?  Under-inflated tires can effect gas mileage because it causes more friction requiring your engine to work harder.  A lot of newer vehicles have a convenient tire pressure monitor in the computer menu. Some will even alert your if your tire pressure it too low. Tires can be expensive, don't waste money by having to replace tires due to poor tire care.