Does anyone know the best way to travel from Rennes to San Se? Is there a good website for trains or bus routes?

Yo Davo!
Is Brittany/Rennes in France, by chance?

Hi
Yes, I want to come down into Spain via the Pyrenees, instead of having to go via Paris? Do you know if the buses or trains go that way?

I am pretty sure you're going to have to go through Paris. You could take a TGV to Gare Montparnasse (2 hours) and then switch trains there (same station) and catch another TGV...to Hendaye (5 hours). In Hendaye you walk to the Irun train station (2 minutes) and catch a train or bus to Donostia. Hope this helps! Check out http://www.voyages-sncf.com for schedules and prices.