First place to look will be a good map in an atlas or a book on France from your local library or bookshop. This will give you the names of the areas bordering on the Mediterranean, the big towns and the resorts.

You can then choose the ones that you like best and use the internet to look up 'town x office de tourisme' which should give you information for the area.

But do note a couple of things. The South of France is very hot during the summer, and there are massive traffic jams to get to beaches, which are not necessarily sandy nor free. The costs of accommodation are very high, and finally the area is heaving with French locals and Parisians all there for their holidays too. I would suggest you look elsewhere, as package holidays are not as common to this destination as to Spain, Greece, Tunisia, Morocco, Turkey or Bulgaria.

Hi

We have 2 brand new luxury mobile homes to let on the Cote D'Azur if thats what your interested in? or do you want an hotel?
Please see our website for more info.
Mandy

I'm looking for a holiday in the sun on the coast

That narrows it down a great deal. The sunny coast is the Mediterranean coast, which is a little more expensive than similar vacations in Spain. Stay in a coastal city with an excursion into the country villages. Any good tour guide will tell you what you want to know.