Hey:
I started the Camino on July 14th, 2007 in St. Jean, and finished on August 24th, 2007 in Santiago.
I flew to Paris CDG from Portland, Oregon, and then took the fast train from CDG to Bordeaux. Spent 3 nights there - nice town just to relax in and get mentally prepared. Bought a Nalgene Narrow Mouth water bottle, two Leki walking sticks, and a pack liner at a small outdoor store there. Despite the language barrier (my French is pretty basic), they were helpful, especially the guy who instructed me on the proper use of the sticks.
Then, took a train to Bayonne and spent a day there - another good place to take a day and prep. Bought a zip-up rain poncho at a large sporting goods store (long walk from downtown) that covered both me and my pack. All the items I bought in France served me well, but due to the dollar's low value (and France being kind of expensive) I'm sure I paid more than if I'd gotten those items at home.
Finally, the next morning I took a train to St. Jean and spent a day there before beginning the Camino early the next morning. Looking back, I'm glad I didn't have to rush to St. Jean or rush thru the Camino - wouldn't have worked out if that had been the case. Plus, I got to see some cool parts of France.
After reaching Santiago and staying for a couple of nights, I took a bus from there to Paris. Not sure I'd recommend that - it was a 25-hour ride (with some breaks here and there, but still...ugh). I hung out in Paris for 3 nights, then caught the shuttle bus from Opera to CDG and flew home early (my original ticket had me departing from CDG on Sept 5th, but I chose to leave on August 31st - had to pay extra to do that, but worth it because I missed home).
Overall, I guess you could say I basically winged it. Had no train or bus reservations - bought everything on site the day of departure. Goes to show that you can get around in Europe a lot easier than the States. Buen Camino!