In reply to BossHog:
There is no perfect guide, we end up taking all of them! The jingo one is fairly extensive, and there is an updated version of the purple guide (now white) that is better than the old one.
The real classic areas are Bas Cuvier, Isatis, Trois Pignons, Elephant, Aprement, plus others. Some nice places we have found are Canche au Merciers, Beauvais, Gros Sablons, Rocher Canon. Sounds like a cop out but check the guidebook for areas that have recommended circuits at the grade you want, so 5-6c means blues, reds, blacks. That way you'll end up with loads of problems at the right grade. Black ciruit at l'elephant sticks in my mind as a good un, I'm sure others will have a favourite.
It might be hot so take your trunks - swimming lake at Bois le Roi. Also 40min train to Paris centre for a bit of tourism.