We recommend using TheFork, a TripAdvisor site and app for booking restaurants in Paris. Not only it is a convenient tool to find the restaurant near you, no matter what part of Paris you are in, exploring a museum or a famous attraction in Paris, but it is also a great way to book a restaurant online, without having to call them. And on top of that, TheFork often has discounts you can use at the restaurant.
Also consider exploring restaurant options from Zagat Paris website. Their information is always up to date.