Our toilet leaked and now the floorboards are wet. What do I do now?

You don't say what the floor is made of and what state is that in? Wood, brown chipboard, green chipboard. If it's literally wooden floorboards it will dry out but may warp a bit, so might need a bit of minor tlc to be good for putting new flooring down. Green chipboard is moisture resistant so it stands a chance of being ok once dried out depending on how long and how much it was wet. Brown chipboard will need replacing, it loses structural strength when wet to the point where you can go through just by stepping on it. It doesn't recover from being well. If it's this then replacement will probably be covered by house insurance.