Spain itinerary

Seville, Ronda and Granada are not east of San Sebastian; they are way to the south.

Please clarify: Have you already bought your airline tickets? Into Madrid and out of ???

You can get projected driving times from viamichelin.com, but you should pad them since folks on this forum believe they are generally too optimistic. You will spend a lot of time in the car if you drive from Madrid all the way north to the Basque Country, then all the way south to Andalucia, then all the way back north to Barcelona.

Depending on your ultimate itinerary, the train may be faster for part of your trip. I find the Deutsche Bahn website the easiest to use for checking schedules, though to see fares you'll need to go to renfe.com.

A flight within Spain may make sense, because neither Granada nor San Sebastian is quick to reach from Madrid or Barcelona if you're traveling by car or train. You can check flight options on skyscanner.com.

The Basque Country is quite a bit cooler than your other destinations, so hitting it early in your trip is a good idea if you can fit it into a geographically sensible route.

I suggest you sit down with a map and viamichelin.com and see which connections are feasible by car, which by train, and which might be better done by flying. Also, you'll want to avoid doubling back. Vueling is a Spanish budget airline that connects lots of your destinations. Granada to Barcelona, for example, is a quite long drive. Since we were last in Spain, some of your cities have been linked by high speed trains. When you compare train vs plane take into account the pre-flight time you need these days and the fact that trains take you into city centers, while airports are generally out on perimeters.
If you haven't bought your tickets, the most sensible thing to do would be to fly into Madrid and out of Barcelona.

Thanks to both of you for the replies. Acraven, we have only purchased our San Diego-Madrid flight. Will buy the return once we figure out the remainder of the trip. We weren't thinking of driving the whole way, but rather one leg-either Madrid-San Sebastian or Granada-Barcelona. I'll check the michelin site for that (thanks.) Renfe gives me a message that the trip I want isn't available yet, so Deutsche Bahn will be helpful. Also, to clarify, I do realize that I originally wrote EAST from SS to Granada. My mistake, I knew it was west.

DB won't have your schedule if Renfe doesn't, I don't think. Use a date that's about as far out as you can go, on the same day of the week you anticipate traveling. Perhaps the seasonal schedule change is due in the meantime. Another possibility is that you're running up against Renfe's reluctance to price a compound trip on which you change trains in Madrid (such as between Granada and Barcelona).

Oh: For trips to or from Madrid you want Puerta de Atocha Station, not Atocha Cercanias.

From Madrid to San Sebastian, direct trains depart from Madrid Chamartin station and take either 5.5 hours (8:00 or 16:00 departures) or 7.5 hours on other departures.

You can fly nonstop from Bilbao to Sevilla (but not from San Sebastian nor to Granada); try www.skyscanner.com.

train schedules don't change much. You can look at the trains for next week, just pick the day of the week you plan to travel. Expect the same schedule for that day of the week for September. The only change would be if there's a holiday.