It will cover things like the difference between a baffle (Item scanned into location but physically not there) and a ghost (Item in location but not scanned in), the PULL application, the STO application, I think SUBT is covered as well. It also has best practice things such as how many different items should be in a case stock location, how many different items should be in a waco, how should things be stored in openstock (side by side, tall items behind short, etc), zoning the stockroom, I think thats most of it but its been a couple years since I had to take it so they may have modified it
The backroom certification quiz? It's a piece of cake; basically everything that FlowMonkey said. You need to score at least 80% to pass it I believe, but you can take it as many times as you need to in one sitting until you do pass it.
It also covers safety, such as when using the ladder, use three points of contact, which is to have both feet planted, and one hand holding on the the side bar. But its really easy, just read the questions carefully.