In reply to aehaas:
Pads can be rented at S'cape shop (
http://www.scape-shop.com ), the Karma climbing gym in Fontainebleau (
http://karma.ffme.fr ), a pizza place in Arbonne-la-Forêt (by the roundabout in the village center) and maybe at this gîte in Ury:
http://gite77ury.com/language/fr/tarifs .
I suppose it's easy to find partners as long as you're more social than I am (which is fairly easy), especially if you go to the popular areas and try the "classics". If you don't have a car, the quickest areas to access by foot are Petit Bois (stop at Nemours, then it's a 20-30mn walk; it's a very shaded area which is good if it's hot) and Rocher Canon (stop at Bois-le-Roi, then it's a 20mn walk).