How do you check your fire extinguisher to make sure it works properly and where can I purchase a new one in case it doesn't?

To check if your fire extinguisher is working properly you should check the plastic seal holding the pin in the handle. If it has been removed or tampered with you should contact your local fire department. Also, check the gauge and the weight of the fire extinguisher, if it is not full, you will have to get it recharged. If you are looking to purchase one for your home, Home Depot and Sears carry them, along with other stores like them.