Although the cemeteries of Paris are some of the most visited sites in the city -- more than a million tourists visited Pere Lachaise last year alone -- there are few guides available, in English at any rate. The only known guide is the Culbertson/Randall book and it is woefully out-of-date and contains quite a number of inacurracies.
The Barozzi book is also dated as well (1990) but his maps are excellent, worth the cost of the book alone.
The best book by far is Bertrand Beyern's Guide des tombe d'hommes celebres. It not only features those famous (and infamous) buried in Paris but covers all of France as well. He, too, has excellent maps of the city's major cemeteries.You will probably have to wait to find a copy after coming to Paris. The 2003 eidition is widely available in the city bookshops. In French only
Another excellent print resources is Valverde/Hughes Le cimetiere du Pere-Lachaise. Outstanding photographs, up-to-date (2007), with superb maps of the cemetery, this is one book you will want to have in hand to seriously explore Pere Lachaise. In French.