Restaurants I like: Au Bougnat (just behind the Notre-Dame), La Tête d’Ailleurs (Bastille IIRC), l’Avant Goût (just down from the Place d’Italie). If you want good cheap eats then head to the Jewish bit, Rue des Rosiers, for great kebabs etc. There are lots of places to eat on the left bank: the Latin Quarter, the Odéon etc, if you like to browse lots of things in a small area. Just don’t bother with pasta anywhere because for some reason the French are hopeless at it.
Sight-wise, be prepared to queue for the big attractions. The Louvre (which is massive – it’d take a week to do it all) and the Eiffel Tower (which is pretty cool if you go all the way up) will normally have massive queues. I liked the permanent exhibits in the Pompidou. But I always think the best sights in most cities are the backstreets and the everyday stuff going on – YMMV 🙂