Love that job

I really do enjoy my work at the library. The pay is good and most of what I do is enjoyable.
But... I want to live a life that is simple. Less stuff to buy or bills to pay and more time to do what I want, even if it's just a nap.
We have cut down on so much, and we don't have too many bills (mortgage, car payment, utilities, insurance, gas and food), but they still need to be paid every month.
After the car and house is paid off, how many hours would I really need to work to pay the bills.
I want to find out, and the sooner, the better.