The number 1 thing I suggest asking about is tuition and fees, as well as what options are available to help counter the cost (grad assistant positions, TA positions, scholarships, etc). Not all programs are great about advertising that on their websites. If you are out of state, some schools have the option for you to be considered in-state your second year so you get to pay in-state tuition your second year which is nice. Some schools don't have a difference between in-state or out-state tuition. It's all very messy and confusing, so that's something I always like to clarify and get specific details on.