Currently, as a British national, you benefit from EU automatic free movement rights to come and live in France.
This is unconditional if you are working, whether employed or self-employed (as long as the activity is not just occasional), and you have no need to seek a work permit. Jobseekers have a right to stay at least six months and non-workers, that is early-retirees and state pensioners, can stay indefinitely though, in theory, this is on condition of having enough means so as not to be a burden on social welfare and being covered for healthcare (if you have an S1 or you are accepted onto the state Puma system, usually involving an annual subscription payment, then this fulfils the latter requirement). After five years of legal residence, EU citizens acquire a right of permanent residence.
EU citizens have the right to bring their spouse with them and there are no further conditions attached to the spouse’s residence if they are also from an EU country (or EEA or Switzerland).
However if your wife is from a non-EU country she must apply (free of charge) for a carte de séjour ‘de membre de famille d’un citoyen de l’Union/EEE/Suisse’ within three months of arrival. This gives the same rights as your own. Documents required for the card include a copy of the marriage certificate and ones proving your own legal residence status (such as work contract and/or bank statements). A civil partner or informal long-term partner of non-EU nationality may also be able to live with an EU citizen if they have evidence of living together for more than a year (civil partner) or five years (other partner).
If Brexit goes ahead as planned, this situation will remain until the end of the planned transition period in 2020. After that Britons are expected to be considered ‘third country’ citizens (as opposed to EU citizens) and the rules will be different.
Then you would both apply for cartes de séjour and/or visas separately but prefectures will consider the two carte de séjour requests together for practical reasons. If one is refused, under some circumstances it may be possible for the person to request a temporary card for ‘vie privée et familiale’ with proof of marriage.
If one of you came first and wished to bring the other over, rules on regroupement familial might apply (depending on circumstances) including having resided legally in France for at least 18 months, having a home of a sufficient size for your family and having, between you, income above a certain level.