Folks - I hate to sound like a pessimist. BUT - having signed a few leases and contracts, I'll never do so again without advice of a professional. As Stacy said, LAWS do change and I want to be protected. I've encountered too many surprises in France (and in the US as well) that I don't want to go there again.
Small print in English is hard enough. In French (coupled with the Napoleonic Code) -- you're asking for trouble.
For example - certain "details" as the taxe fonciere and even having to pay a tax if you own a TV!
Another thing to be aware of:
If renting an unfurnished apartment, the "dépôt de garantie" cannot exceed 1 month's rent.
If renting a furnished apartment, the landlord can ask pretty much whatever he wants.
In either case, the amount calculated (whether 1 month, 2 months, or other) is to be based on the amount of rent only, not including charges.
(This is according to the current laws, but note that the laws do change from time to time so you will want to keep yourself informed and/or check with a lawyer before signing a lease)
We have learned the hard way that there are often additional fees that will come along with your lease. Make certain that the amount you agree on is "complete" otherwise you will face hefty bills for things such as garbage pickup!