Everyone on here stresses the importance of changing transmission fluid. To me this is one of the most important maintenance activities that can save you real money on expensive repairs. When you see what is behind the pan, I think it will bring home the importance of keeping the ATF fresh. Heat is definitely the transmission's enemy..
Personally I like to use an ATF that meets the JASO 1A standard. Though this post is not intended to start an ATF fluid debate, there are top shelf fluids used by members that meet this Japanese quality standard.
Here's a picture with the pan off during my first fluid change. I cleaned the pan magnet, replaced the strainer, o-ring, drain plug crush washer, and installed a new gasket and pan bolts.
Now that I'm certain about the condition of the strainer, o-ring, and gasket, I change fluid using an extractor pump. The extractor pump tube can hit the pan bottom and extract approximately 5 quarts with each change.
Two pictures with the strainer on the transmission below. As you can see from the second picture, the strainer is just that.
These two pictures are intended to show the intricate components and electronics that are submerged in ATF.
