I have been asked by a few people for the route, not sure if I should post here or on a new thread so please advise if it is wrong.
Our route was pretty straightforward.
We borrowed some of it from the experts - Donald Hirsch and Howie from a different website, plus some good advice from JackE
For the section on the canal into Paris we used
http://pgoh13.free.fr/velo_english.html
As for Paris itself, we just blagged it and pointed our bikes towards the pointy tower!
If anyone wants any more info, please just let me know.
But bear in mind there are other routes available that have been done by cyclists that have far more experience and local knowledge than us.
Overview
From Dieppe to Avenue Verte:
From Forges les Eaux
to Gournay
From Gournay McDonald's to D2
D2 to Auteuil
Auteuil to Ully St Georges
Ully to Blaincourt les Precy
Blaincourt to Foret to Chantilly
Chantilly to Plailly
Plailly to Saint Mard
St Mard to Gressy