Once you arrive in France, spend some time learning about the judicial system of both the country and your new region. There may be subtle nuances that differ from life in the UK - the accepted blood alcohol level when driving, for example. Find out what is (and isn't!) acceptable behaviour.
France is a well policed country and actually has three national police forces. The Police Nationale (previously the Surete) is a civilian force, responsible for major cities, whilst the Gendarmerie Nationale is responsible for smaller towns, rural areas and all the military bases in France. Lastly, the Direction Generale des Douanes et Droits Indirects is a civilian service known more commonly as Douane. It is the Gendarmerie that you are most likely to see around and about, and you should remember that they are armed at all times.
The crime rate in France is generally similar to other European countries. There is a general policy of tough sentences being given out in an attempt to deter serious crime, and drug crimes are taken particularly seriously and dealt with as such. Prison population figures remain fairly high, but it is important to remember that the ratio of prisoners compared to the general population is much lower than in the UK. As with the majority of other European countries, there is no death penalty in France.
Driving laws have become much tougher in recent times, with a huge clamp down on drink driving. The blood to alcohol level permitted is lower than in the UK, and since 2012 it is mandatory to cary an alcohol breath test in your car. We would recommend carrying two of these, as each can only be used once. The tests cost a couple of euros from garages and larger stores, and there is an €11 (approx. £8) fine for non-compliance.
Radar speed cameras are increasingly in use on motorways and other major roads, with anyone caught speeding (or for another minor traffic offence) will either receive an on the spot fine or will be notified by a letter which includes the fine; this fine will increase if it is not paid within two weeks. High visibility jackets (normally yellow) and red warning triangles must also be carried at all times.
In general, crime rates in France are really no worse or better than any other western country. Some larger cities such as Marseille and Nice do have a reputation for criminal activity, but in general most areas have few crime problems and smaller villages are normally pretty safe. Crime against properties is fairly prevalent in some areas, with holiday homes often being the target so it is sensible to take normal security precautions.
It is never a good idea to let too many people know if you are going to be away for some time. People chat in rural communities and it is better to be safe than sorry! Having said that, most of rural France is well protected by the various police forces and local police maintain a high level of vigilance. There is no particular bad feeling against expats; indeed the police are used to the English invasion in their towns and villages!
The use of drugs, alcohol and cigarettes is as prevalent amongst the young folk as it is in the UK, and in some quieter regions there has been a problem with drug taking. However, the use of cannabis has been decreasing generally and although alcohol is widely consumed in France, there is not quite the same problem of youth drink abuse. The French as a nation tend to enjoy their alcohol without using it primarily in order to get drunk. French children are brought up to have a small taste of wine with meals, and most bars close by around 11 pm except in the larger cities.
Some useful emergency numbers: 15 is the general one for medical help (SAMU), 17 is for the police and 18 is for fire.