To keep your car's air conditioning system in good repair, you want to have a mechanic inspect the compressor, condenser, and other pieces every year, preferably before summertime when you'll be putting so many demands on the system. However, there are some things you can do on your own to keep the air conditioner in good repair and to avoid excessive wear and tear. Note a few of those here and discuss them with your mechanic if you still need more information about your car's A/C system.
Run the air conditioner every week, even in wintertime
It might seem like a contradiction that you want to run the air conditioner regularly to avoid excessive wear and tear, but there is a good reason to do this. Running the system maintains the pressure of the gas in the compressor that is needed for the air conditioner to work. If the gas pressure gets low, this can mean the compressor works harder to create and circulate cold air. Run the air conditioner every week even if you don't need to; this means turning it on to full power and letting it run for several minutes so the pressure builds up in the system and the compressor continues to work properly.
Run the window defrost system every week
Your window's defrost system uses warm air to melt away ice and snow on the outside of the windscreen, but it also dries up humidity and moisture in the dashboard fan and other areas of the cooling system. Too much humidity in the air conditioner can mean that mold and mildew grow in the system; this can cause very bad odors and also cause the system to work harder to blow cold air through the vents.
Vacuum and clean the vents
When washing your car or cleaning the inside, you may not think much of the vents on the dashboard or above the floorboards. However, dust and dirt can accumulate in these vents very easily. In turn, your car's air conditioner needs to work harder to push air through. This dust and dirt can then also travel down the vents and into the system itself. You don't want to start removing vents and getting too ambitious with cleaning as this can mean suctioning up parts from the air conditioner system, but it's good to wipe down those vents and the slats of the vents and use a car vacuum hose over their fronts to get them as clean as possible.