Next Year's Property Taxes

Does anyone know the guidelines that the County uses to value a particular home---say one with no additions or improvements?
I have heard that the appraised value is the biggest factor, but I have also heard that it depends upon what homes in that area have sold for in recent sales.
It has become obvious that homes are not selling very well at all now due to the loan crisis. They also are selling more cheaply.
Also, I heard during the congressional hearings that "appraisers" have consistently been overvaluing homes in order for banks to be able to loan more than the homes are worth.
Of course the mil rate can also be raised within certain limitations in order to meet an approved budget.
Has anyone ever heard of personnel lay-offs occurring in the Counties and Cities under circumstances that we now have in that industry? Or, how about reductions in salaries?
I just am curious as to how all this will effect my taxes next year on my property.
It is already a problem in that when my home increases in value it puts no more cash into my pocket with which to pay the ever increasing bills! If I sell it for the money, I'm out of a home!