Tax consultant and a lawyer, because I expect them to help me planing out everything. I'm pretty sure that I'd be way too overwhelmed with that much money, otherwise.
No clue what I would actually do with that much money. All I currently really want is to live a simple life, with a nice enough home, maybe a nicer car and then I'd worry about providing help to my loved ones. I would also absolutely look into charity, project funding, important research and other things that would benefit others. It actuallly makes me depressed, when I hear the stories of millionaires/billionaires and how they spend their money on absolutely ridiculous and completely useless stuff.
But I have heard the stories about money changing people (yourself and others), so I'm gonna be honest and say that I actually have no clue what would happen in reality... and that is a really scary thought for me.