There are hotels available near all the three major cemeteries. I recommend using booking.com -- and the revenue helps keep this site online:

If you're going to be in Paris for longer than a few days you'll most likely want to rent an apartment.

The bad news is that many of available apartments are managed through rental agents and they charge a hefty commission (usually in the hundreds of Euros). Remember: generally speaking the longer you rent the less expensve the per month cost will be.

In Paris there is a wonderful (and free) resource called FUSAC (France USA Contacts), which is where we found our apartment rental in the 5th arr. in 2006 (and rented from the same person again in 2007, 2008 and 2009 in the 11th).