"...on taking a month to do it...starting from st jean pied de port..."
A month should be long enough, some take a little longer, if your time is your own try to be more flexible and give yourself a little longer.
Many people start at
Saint-Jean-Pied-de-Port but I don't see why, it isn't that easy a place to get to (even if you fly to Biarritz), it is pretty enough but quite touristy and more importantly your first day on the walk has you climbing a very steep route over the mountains. Much better (I would suggest) to fly to Barcelona or Pamplona and then by train or bus to the monastery at
Roncesvalles which is where the Spanish walkers generally begin.
If you can find the time and you want to see some of
Camino route in France consider taking a train from Paris to
Moissac, that'll give you ten to twelve days in France and will take you into the
French Basque country, probably one of the most beautiful parts of France and certainly home to one of the most generous and friendly people in Europe.
If you are Catholic then the arrival at Santiago may provide a 'good end' to your camino, however many people like to walk for a few more days and end their journey at
Cabo Fisterra on the Atlantic coast, this is definitly something that I'd recommend whatever your faith.
Buen Camino.
Edited to add:
Here is a link for a PDF of a topographic map dividing the way in Spain in to 27 sections.
LINK