I can't really answer your question directly since I'm in UK, but I can say that once the game had some success I went straight to an accountant to form a Limit

I can't really answer your question directly since I'm in UK, but I can say that once the game had some success I went straight to an accountant to form a Limited company. That accountant now deals with the money side of things, so I can stay focused on the games (plus I'm terrible with money). That separation of concerns is, I suspect, a lot easier when there's only one person in the business! Additionally I didn't do much in terms of legal contracts with the first game (mostly stock assets with just the character art being commissioned), but for my new game I've had a lawyer draw up contracts for any major pieces of work.