One of the most useful things I found in the 'Documents VFR' pack is the 1:1000000 map (two of them in fact, one for the north and one for the south). The IGN charts only cover airspace up to 5000 feet and I had to use three of them for a flight last week from Geneva to the UK. Major chart folding exercise required!!
Seems that once you are above 5000 feet you will be flying in the airways which are all marked on the 1:1000000 charts. You have to fly using the semicircular rule at the appropriate FL for your track.
What I am still trying to find out is whether once you are above 5000 feet you can go places where there is no airway marked or whether you *have* to follow the airways. At one point ATC seemed quite happy for us to route direct from one VOR to another which had no airway joining them. They simply asked us to fly at the correct FL and to carry on. I'd like to get to the bottom of this before I go again!
Have fun talking to Paris Information - they don't seem very big on information, but I guess they must be in Paris somewhere!!!