There is of course quality housing with charm in every quartier, but a notion of each area might be helpful in deciding where to look and what to consider. The following comments should be especially useful when having to select a neighborhood sight unseen.
One of your first purchases in Paris should be a small square red or black book called Plan de Paris par Arrondissements, which includes detailed maps, a street and métro index, and bus routes. It´ll cost you around 100 FF. This is indispensable for finding your way around Paris. Trust this advice, you´ll need a plan. Carry it at all times.