You will also need to decide in which region of France you'd like to live.  Most people choose either Paris, the overseas territories or the southern coast in places such as Nice.   These are exciting and beautiful places, but try to avoid these for several reasons:  these are also the most expensive places in which to live, they have the most American tourists, and choosing these places could ruin your chances of being accepted into the program.   You're essentially given three options; I chose the North (near Lille) as a second choice and was placed there.  Although the North may not look as charming as elsewhere in France, the people are the warmest, the culture is unique, and the location is superb—less than 2 hours by train from Paris, London, and Brussels.

By then, the most sound advice would be to be patient.  This will have been during the summer while many French education employees are on summer vacation.   Don't expect to hear any responses until late August at the earliest.  Similarly, don't expect to receive your arrêté de nomination (an important piece of paper showing that you've been officially hired), which is needed for your visa, until the end of August.   Once you have received your information, take it, your visa applications, passport, your birth certificate, several passport-sized photos, and three copies of everything to the closest French embassy or consulate (or mail them) in order to get your visa.   Afterwards, I suggest that you go to a notary public (who is also a translator), or a certified translator to get your birth certificate translated into French.   All of these items will be necessary for payroll.  

Once these things are done, you'll feel a lot calmer and more excited about living in France. 

Thus, by the end of August you should have contacted your school, introduced yourself, and asked if housing was available on campus—in French, of course.   If no housing is available, then ask if they could recommend anything that would be cheap or about what was previously rented by a former language assistant at the school.  Housing in France can be somewhat cheaper than in most large American cities. 

In a moderate sized city, a one bedroom flat shouldn't cost more than 350 euros.   I worked at a teachers' training institute and paid about 140 euros a month for a huge furnished bedroom, private bathroom, shared kitchen, use of an entertainment lounge, computers, gym, etc.   Others in similarly sized towns paid anywhere from 250 to 450 euros depending on what types of accommodations they wanted.  

One great thing about the language assistants program is the ability to network quickly.  All new language assistants have the same questions and problems and are looking to talk to anyone who will listen or offer some comforting advice.   It would behoove you to make connections with the people in your region as you will undoubtedly reencounter them.  Networking is simple with www.AssistantsinFrance.com.  You may even find someone with whom to split the rent. 

Bring bank cards and or a credit card and some cash for the airport/transportation.  Although you could exchange your American currency, using ATM cards is the easiest and cheapest way to get Euros.  In France, ATMs have no fees whatsoever and your VISA or MasterCard will work just about anywhere and give you the exact exchange rate.  Besides, in order to pay for transportation and lodging on your day of arrival, you’ll need access to Euros. 

If you don't have housing, look in the local paper's classified section ("les annonces") for small apartments rented to students.   Also, people post apartment vacancies on bulletin boards at the post office and in and around universities.  Ask any of the locals that you have met if they know anyone who's renting an apartment.   You'd be surprised at how helpful the French can be. 

After you've settled in France, ask your landlord to give you a renter's statement "attestation du logement," then go to open a bank account.   You will not be paid without a French bank account.  This is not a difficult task and if you need help, ask one of your professors or a fellow assistant who could ease the French communication.  Banks usually require an appointment beforehand but sometimes, there’s time for a walk-in.  If you are under 26 you will benefit from free checking at most banks.  Just bring to the bank your passport and renter's statement and you should be ready.  

Before you begin working, make sure that you've filled out the documents necessary for payroll.  If you have questions, ask your school's director.   It will include your translated birth certificate, bank account identification card, arrêté de nomination, etc.  Last, go to your regional prefecture and apply for your long stay card.   First you'll need a medical examination and the directions will thereafter be mailed to you.  Once you have taken your examination, return your doctor's form to the prefecture along with everything that you took to get your visa.   Within a few weeks, you should have your long stay visa, and can breathe another sigh of relief.