Pick up a copy of Pariscope, which is published weekly, and contains information about museums, exhibitions, films, etc. 

The official Paris tourism website is  is an excellent source of information, and is sponsored by the city of Paris. Note that there is an English version that can be reached by clicking on the small tab in the upper right corner of the screen marked.

Off the beaten track....

In Paris

In the 4th

Le Musée National du Moyen Age is housed in two Parisian monuments: Gallo-Roman baths from the 1st - 3rd centuries and the late 15th century Cluny Abbey.  Beware that the collection is very large, and you can develop a bad case of museum legs by  lingering over reliquaries containing the left fingernail of  Saint Oyand.  Unless you are  devoted to such  things, stroll  through the museum  to the  famous Lady and the Unicorn tapestry, and enjoy the large brightly lit room containing Roman sculpture.

Le Panthéon, which is the permanent home of some of France's greatest personages, has been recently cleaned up, so it has lost some of its creepiness.  But the building and the crypts are very much worth a visit.

In the 6th

Le Musée Marmottan Monet has an outstanding collection of paintings by Monet as well as well-known works by Manet, Renoir and Caillebotte.  There is also a collection of illuminated manuscripts.  Very much off the beaten track in the 16^th arrondissment, not far from the Bois de Boulogne. 

In the 8th

Le Musée Jacquemart-André claims to be the “most sumptuous dwelling in Paris.”  This small museum is located on the Boulevard Haussmann, and can be enjoyed for its ambiance as much as for its art collection.  

Le Musée Nissin de Comondo is an early twentieth-century home of a family of Turkish bankers who settled in France during the mid-1800's. The building and collections are impressive, but the powerful story of the Comondo family, which was wiped out during the Nazi occupation, is what stays with you.

Le Musée Grévin used to be a seedy wax museum with two extraordinary Belle Epoch features: the Grévin Theatre and the Palais des Mirages.  There used to be a short and rather strange magic show in the theatre, and, a hundred years ago, the Palais was a high-tech multi media experience.  The museum has been renovated, so it's more of a run-of-the-mill wax museum.  The Palais des Mirages has been restored and updated, and the old dusty installations such as “The Assassination of Marat” along with "Marilyn Monroe meets General de Gaulle" have been cleaned up. But there is something amusing about the Gallic slant of the place.

The covered passages of Paris used to be similarly seedy. They were constructed during the first half of the Nineteenth Century, and were, at the time, very stylish. A hundred years later, they had fallen on hard times. Today, many have been cleaned up and are respectable. But some are still somewhat run down, and are home to strange shops that specialize in astrology and the occult, French postcards and antique dental tools.

 Le Château de Chantilly avec le Musée Condé  Less than one hour by train from Paris, the Château contains one of the largest collections of historical paintings in France.  Have lunch in the town and take a magical walk through the forest to the Chateau.

 Malmaison was the Joséphine Bonaparte’s home from 1799 to 1814. The museum houses an extensive collection of things Napoleon, and is wonderfully melancholy.  Great for a dark mid-winter afternoon.