I went there this summer. It's lovely to walk along by the river, go to Tribana and watch some flamenco dancing, the department store El Corte Inges is like a Spanish JL. Take an open top bus ride around Seville. The ticket is open for 24 hours, so we went for a ride in the morning and then at night time when the city was all lit up.
There are wonderful tapas bars and the trams are a good way to get around and you can also hire bikes as there are lots of bike paths. We also went by high speed train to Cordoba which is a fab medieval town. Enjoy!
Haven't been there for nearly ten years now, but, when you go, get a recommendation from a local for a bar that sells vino de naranja (wine made from oranges) - goes down v. nicely. Also, while the main cathedral is great to visit, in the typical gloomy/violent death type that is old Spanish Catholicism, avoid eating at the restaurants around the square unless you have a recommendation - most tend to be over-priced tourist traps.
Getting someone knowledgeable in the mudejar style and period to show you around a few hidden gems is also good. Should you wish to head outside of the city, there's a fast train to Cordoba. The old city there is well worth a visit.
My friend and I are off to Seville in two weeks. It's a last minute choice of destination, we were due to go on a cooking/ drinking/ sight seeing trip to a place just outside Venice, but the lovely Secret Escapes cancelled it 18 days before departure, thanks. So as all the child care/ dog sitter and school run substitutes were in place, we have come up with a trip to Seville instead! I've ordered a guide book, but has anyone got any tips for sight seeing, shopping and eating please?