Been there a few times. I followed the ABB - PON - RBT line and had no trouble. Spotting the airfield can be difficult unless you do your VOR NAV very carefully, and Villacoublay isn't far away (you'll see it). If you go to Sierra and then head North, you'll see the field OK!
If there isn't much around, you may (if you're lucky) get a direct join without the dogleg via RBT.
Watch out for them putting local traffic onto final on the other runway. I had a French PA28 cross in front of me on final approach, 200 feet below, to get to 28R while I was aiming for 28L. Scared the **** out of me.
Fabulous trip - and a short taxi ride to the Palais de Versailles, or to the railway station to get to central Paris.