From the UK to Calais take the ferry (23 saillings daily) from Dover or the Eurotunnel (46 crossings daily) from Folkstone.
The main companies that operate direct ferries on Dover - Calais are: P&0 Ferries, MyFerryLinks (previously owned and operated by Seafrance) and DFDS Seaways (previously the Norfolk Line).
Crossing the channel on a conventional ferry takes about 90 minutes and starts from about £70.
The Eurotunnel transfer is the fastest, only 35 minutes, but also the most expensive, from £130. If you book early you can get some good deals.
The preferred route is Calais > Reims > Dijon > Geneva > Chamonix. It's about 560 Miles (900 km) from Calais to Chamonix (via Dijon) with a drive time of about 9 hours. All but the last twenty kilometers are on the motorway. The motorways in France are toll roads called "Autoroutes" or the "Peage". Autoroute tolls are approximately €80 one way.
If you are not in a hurry, and want to cut out the toll roads, there is a route through Belgium, Germany and Switzerland. Even if it is a little further, depending on your car's fuel consumption, you can save some money. This route is about 300km longer, there are no road toll but there is road tax of £25. The journey can take up to 13 hours.
To plan your route consult the ViaMichelin Route Planner or The AA Route Planner.
To see what is happening on the roads in France, check out BisonFute, site run by the French government. The Autorutes, run by the French Motorway Companies.
Driving back to London, follow signs to Geneva, Dijon, Chaumont, Reims and Calais.
French law requires you to have a reflective vest handy in the car as well as an emergency warning triangle. Non-compliance could result in a 90-135 Euro fine.
From 2012, you must also carry an approved breathalyser kit in your car. Read more about French driving regulations from the RAC.
In winter, it’s a legal requirement to carry a set of snow chains. Attention! Snowsocks for tyres do not conform to French regulations!
(Ouvert = Open; Fermé = Closed; Equipements Spéciaux Obligatoires = Special Equipement, e.g. Chains, is necessary)
Ensure you have Valid Registration Documents!