p.s. Just remembered the black girl in the series 'Canguros' when she found she was babysitting a kid so that the parents could join a Holy Week procession as 'penitentes' (http://www.sanjuanresucitado.com/tercio....
I've been there, and I didn't experience any culture shock (although I was a Spanish minor in college, which may have helped). The biggest - and really only - difference for me was mealtimes. Dinner at 10pm is not unusual there, nor is staying out until 5am. Don't plan on getting to dinner or bars/clubs too early unless you want to look like a dork like I did :)
Topless on all the beaches is not only legal but also quite usual in Spain.
Even if most Spaniards are Catholic because they have been baptized, very few of them attend the mass at church, and they are usually old people. In the USA there are many more people who believe in God than in Spain.
Like in the rest of the world except in the USA, soccer is called football and is the most popular sport, even if basketball is the second most popular one in Spain.
In Spain not only Spanish is spoken but also other languages, which are official: Catalan/Valencian, Galician and Basque.
Spain is in Europe and not in Latin-America, as many people from the USA still think.
Spaniards are white, like Italians or Greeks.
The atomic bombs which lost the US Airforce in the province of Almería. The bombs were found, but the rest of the mess (polluted soil) not cleand up. More than time to clean this up and take the polluted soil to the US.