Just some random notes on our recent trip. First, the tips I received this forum were extremely valuable, and made our trip more fun and relatively problem free. Secondly, I'd recommend learning as much Spanish as possible. Even in Madrid, even moderately fluent English speakers were not that prevalent. Not that I EXPECT Spanish people to speak English, I'm just saying be prepared. Google translate was helpful, too. I'd also say that the Spanish people we came in contact wanted to be helpful and really worked to communicate.
Madrid Airport--It really wasn't all that clear from any signage what terminal we landed at, at least to me. Delta flights typically come in at 1 or 4. The train to Atocha is at T4. Our flights arrived and departed T1. A bus runs between the terminals. Upon landing, I'd ask the airline representative what terminal you are at. We ended up asking someone at an official looking counter (that spoke no English) "tren Atocha" and they pointed to the door and said "autobus to cuatro" The bus between the terminals was a little hard to find. It's lime green and blue. On my trip to home, the bus was across the street on a median. A slight scam report--as soon as I walked out the terminal and looked right and left for the bus, a man approached and asked if I was looking for bus to the Delta terminal. I replied yes and he pointed across the street and median and down a bit. I thanked him and starting walking and he followed. I told him I was ok and he continued to follow and it became obvious he wanted a tip. At that point I had no euro coins and the smallest bill was 10euro. I showed him my empty coin pocket and he left. Not a huge deal, and had I had coins, I would not have been upset to give him a bit for the help, however we got offers of help a few times on our trip and it was always folks just being kind and its a bit sad now to think that sometimes it is more than just kindness that motivates folks. But, again, no big deal. In the end, the arrival and logistics to Sevilla were relatively easy especially with help from Enric and Acraven. Renfre at the airport was very helpful and pleasant.
Atocha, is indeed big and wildly busy, but we had little difficulty finding the AVANT and AVE trains. Note you must have a bit of time because you need to clear security and there are about 20 platforms/gates.
Sevilla, is lovely. We stayed at a RS recommended hotel in Santa Cruz (El REY MORO). We enjoyed the stay. The inn has local charm, great breakfast, and is in the perfect location, very close to the cathedral and Alcazar. We were there November 3-5. It was a weekend and it may have been a holiday weekend. It was very busy. I thought we could walk up to the Alcazar and just get tickets. NOPE. We waited more than an hour in line. I would say get advance tickets for any time of the year. We used the time to our advantage, the TI is across that street so we did some planning and we each took some time to walk around and take some photos and the area was good for people watching. For the cathedral, we got to the Church of the Savior at just about opening to visit and get the combo ticket. I think the cathedral line was long, and this way there was no waiting. We enjoyed some time in Triana. Regretfully we went on a Monday and the ceramics museum and shops were closed. (The museum had closed at about 2pm, the day before because it was Sunday) We had gone to the Church of the Macarena and wanted to see the other "favorite" virgin so we stopped by to see Triana's virgin and ate at Las Golondrinas--fabulous! There might be two locations, we ate at Calle Antillano Campos 26.