My husband and I have bought a new home in central VA. The house came with a beautiful hydrangea bush. When we first saw the place, the bush was full of bright blooms. The photo below is what it looks like now.

I want to take good care of this bush and make sure it looks as good in the spring as it did for the previous owner. I also would like it to look neat in the meantime. When should I be pruning this (if at all) and how?