Rick's book covers these cities very well, so heed his advice. Be aware that good hotels in these cities fill up FAST - book yours ASAP.
In Sevilla we had booked a rooom at Hotel Dona Manuela, and although the room and hotel seemed nice enough, the room tey gave us was right over the sidwalk restaurant and was incredibly noisy. It was the worst hotel experience of the trip. We ended up abandoning that hotel and finding a cheap flop-house, which wasn't terribly clean, but was quiet.
In Granada, we stayed at Hotel Anacapri and loved it. The staff there saved our bacon by getting us Alhambra tickets (I was an idiot and didn't arrange them before hand). Highly recommended.
We did Cordoba as a day trip between Sevilla and Madrid, and it worked out fine. I didn't think it warranted a whole day and an overnight, considering all the other places nearby. The great mosque is certainly worthwhile, though. One tip on that: we were there late in the afternoon (maybe just before closing time?), when the sun was low, and the low sunlight coming in filled the place with the most amazing golden light; plus, the crowds of tourists had mostly gone, and the place was just magical. Learn how to take pictures in low light before you get there - some really amazing shots inside.
You're headed for some of the greatest places in Europe. You'll love it.
BTW, if there's any way you can manage it, try to visit some of the white hil towns. If you have to pick one, I'd suggest Arcos de la Fronterra.
Have fun.
