As a programmer, I'm used to have a lot of online books for learning about almost everything.  I'm sure that there are some cookbooks hidden in the web... but I've found just a few of them...  I know that there are a lot of great websites teaching cooking skills and collecting recipes (and my RSS reader is always exploding with great tips and recipes), but sometimes I prefer to have a whole book in my (virtual) shelves...  So I thought we could create a list of available online free cookbooks, like the programming books one on stackoverflow. 
First thing, a cold zone doesn't prevent particulate build up, it just cuts down on the amount that will remain suspended in the oil. You should still filter if you want to keep your oil as long as possible.  You can detect bad oil (meaning rancid) by a few ways, like smoke point or smell. You should store your oil someplace dark and cool, which could be the inside of your fryer as long as you filter and clean the sides before you stick the oil back in.  Another thing you can do to extend the life of your oil is switch to tallow (beef fat) or rended pigs fat (lard) as saturated fats do last a lot longer than the poly-unsaturated.   Once again, you should lose the oil when the smoke point drops, or if it is to dark, or if it develops any foul odor.  And as I said before, once you use the oil once, you should NOT use it past six months under any circumstances, if you do, you are taking your gastro-intestinal tract into your own hands. 