I'm finding almost *too many* resources for this part of the trip planning, but here are some of the more helpful:
Paris Info - this is the official Paris Tourism Website and has a lot of information. In the 'Bed and Breakfast" section I think many people will find exactly the type of accommodation they are looking for in an unfamiliar place - a room in a home with a host who knows Paris.
Parisinfo.com (this is English Version, though note that the Google page translator with chrome is now so good you can surf in many languages. Thanks Google! )
For those who don't want the social interaction of a B and B, there are many hotels to choose from. The usual US consolidators Kayak, Expedia, Hotwire, and Hotels.com seem to have far less options that Venere.com, the European version of those booking services, though even Venere seems to miss the many private residence and B and Bs which are throughout Paris and may offer the best quality for the money.
As a family it's much harder to find the right room, but it would be easy for a couple to find a wonderful room in the heart of Paris *with breakfast* for $100-150 using the following services, all members of the Paris Visitors and Convention Bureau which appear to enforce a set of regulations that govern the quality of the Bed and Breakfast homes on these lists:
