As far as guidebooks go, you have to have multiple in order to get the idea, the general information, the details and the background. No one book has it all, just like no one website can do it all. I like to use Eyewitness Guide Paris, Michelin Green Guide Paris and Pudlo Paris.
Eyewitness Guide Paris seems more designed for American taste. It has pictures/drawings, a great index, maps that are big enough to see and general information as well as hours of operation and good suggestions with short descriptions of hotels and restaurants. Eyewitness Guide Paris provides a starting point, a way to find things you are interested in and begin your list of what you really want to see and visit.
I also like to have the Michelin Green Book Paris because it has details, background and lots of information on its recommended points of interest and a 3 star system. Although it is available everywhere in the United States, Michelin information on hotels is very much geared toward travelers from Europe. Its information on restaurants is also helpful and I especially like the smiling Michelin man licking his chops by those great finds Michelin designates ???????. All of the ones I have tried have been great and reasonably priced.
Pudlo Paris is a great resource for restaurants. I have found some of my favorite restaurants from Pudlo Paris. The author provides accurate descriptions of food and ambience – and with that, you can make choose restaurants that will meet your expectations. As you know, I am not a fan of those reviews that provide a one paragraph description and reviews by people for whom you have no context to understand their review are useless and will set you up for disappointment.