If you are from the United States or Canada you do not need a VISA for France if you plan to be there as a tourist for LESS THAN 90 days.  The 90-day period begins when you enter any of the Schengen group of countries (see below for an explanation).

You WILL need a passport – both to enter France and to re-enter the United States.

British citizens do not need a visa and are allowed to stay for 90 days.

SCHENGEN AGREEMENT
When Europe decided to drop the border controls between countries it was done so under the terms of the Schengen Agreement, so named for the city in Luxembourg where the agreement was signed. This ultimately created a borderless zone that currently consists of 25 European countries.  Access Schengen information by going to:

http://en.wikipedia.org/wiki/Schengen_Area

If you are from a Schengen Agreement country, you will no longer need a visa to travel within Europe.

You will not get a stamp in your passport any longer when you cross the border from one country to another in Europe.  You just drive across the divide – like crossing between states in the U.S.

The United Kingdom and Ireland are not a part of the Schengen Agreement, although they do participate in judicial and police matters that require cooperation.

If you are from a country that requires you to have a French Visa, you will also be able to visit the Schengen Agreement countries on that visa.  However, if you go outside the Schengen area (U.K. for example) you will need to request a French multiple-entry visa.   

FOR STAYS LONGER THAN 90 DAYS:
Please check your local Consulate for the latest in French visa details and requirements, as they are in the process of change. But here is the basic information:

VISA DE SÉJOUR TEMPORAIRE:
You will need to apply for a temporary residency visa if you wish to stay in France longer than ninety (90) days and less than six (6) months.  This application MUST be made at the French Consulate in your area.  Please check our link to the Consulates to find the one closest to you. You cannot go to France without a visa, decide to stay longer than the 90 days allowed, and then request a longer stay. 

The process of obtaining a visa de séjour temporaire is a lengthy one and must be started several months prior to leaving for France.  In fact, it may be wise to get your visa de séjour temporaire BEFORE you book your flight! You must personally go to the French Embassy or Consulate to conclude your application.

If you intend to leave and re-enter the Schengen Area (for example visiting the U.K., which is not a signatory state to the treaty), you have to ask for a “multiple-entry” short term visa!  

To get your visa de séjour temporaire you will need the following:

A passport signed and valid for 3 months AFTER the last day of your stay in France. Bring your original passport as well as a copy for presentation.

Eight (8) application forms (the number varies according to where the information was obtained.  So be safe and bring all eight and you will not be inconvenienced by having to return to the consulate.)

Children will need three (3) copies.  Fill out the forms completely in black ink and sign. Include your telephone numbers and e-mail address.

Eight(8) recent passport-size photos

Proof of residency in the country from which you are applying. Non U.S. or Canadian citizens will need proof of legal residency status for the country in which they reside.

Proof of employment in the country from which you are applying.

Financial guarantees, to include:
A letter from your bank showing that you have sufficient income to live in France.
Proof of retirement pensions or regular incomes, or:
A notarized declaration from your sponsor stating that he/she will be responsible for all your expenses and a proof of his/her financial means.

Proof of medical insurance with coverage valid in France (3 copies). Two letters from your insurance company indicating that the coverage you have will be sufficient.

Proof that you have obtained housing in France, such as lease, promise of a lease, or the title to a property in France. Or a letter from a legal resident of France stating that he will provide for your accommodation.

A non-criminal record certificate to be obtained at the police department in your city of residence (3 copies). It is recommended that you obtain this record as early as possible, since some police stations take a few weeks to issue the record.

A note, dated and signed by the applicant, stating that he/she does not intend to work in France.

For the spouse of a French citizen, the "LIVRET DE FAMILLE", or a copy of a French marriage license, or the official French transcript of the marriage license stating when the marriage took place and where (if the wedding took place outside of France), is necessary. The French citizen must prove his/her nationality as well. Note that an American citizen spouse of a French citizen wishing to live in France does not need a visa. He or she must apply directly for a residency card once in France (with the "livret de famille".)

Processing fee: payment by credit card (Visa, Mastercard) (especially for files sent by mail) or money-order made out to "Consulate General of France" or certified checks. Cash is accepted only if you apply in person. No personal checks. Since these fees change, please verify the exact fee with your consulate. 

LONG-STAY VISA (Visa De Long Séjour)
A long-stay visa allows you to “stay” in France for up to one year.  This visa can be renewed on a yearly basis.  It gives you the right to live in France with certain working restrictions.  Apply for the Visa de Long Séjour from the French Consulate in your area. The process is lengthy, so allow at least three-month’s leeway.

If you plan to retire in France, you will need to demonstrate:

You have the financial means to live in France without working.
You have comprehensive health insurance coverage valid in France.
You have a place to live in France.
You will also have to explain why you want to retire to France.
Once these elements are met, you will be issued a carte de séjour  which gives you permission to live in France, but not to work.  The Carte can be renewed on an annual basis, indefinitely.

RESIDENCY PERMIT (CARTE DE RÉSIDENT)
The Carte de Résident is your long-term permission to reside in France without restrictions on what you do for a living. You have to have been in France on the “séjour” visa for five (5) continuous years before you apply for permanent residency, and the Carte is valid for ten years.  It is renewable.

NON EU-NATIONAL FAMILY MEMBERS:
If the main applicant's visa application is accepted, a spouse and children under 21 years are granted the same rights to live and work in the country. All family members require a carte de séjour; the application process is the same as above. The permit is valid for up to five years, with annual renewals. It is issued at no further cost.

EU Nationals

If you are an EU national you are entitled to live and work in France without a visa.

The U.S. Embassy in France has published a guide for U.S. Citizens Residing in France, called The Blue Book.  Click the following link for a copy:

http://france.usembassy.gov/root/pdfs/bluebook.pdf