Hi, Teri ...
As part of research, I'd buy the Lonely Planet Guide to Barcelona. There is also a terrific magazine called "See" that hits all the high spots. The e-mail address is email@example.com
Maybe they'll send you a copy? I got mine at the hotel and wished I'd had it before.
LaRambla is sort of Barcelona's Main Street ... always busy. We loved the market. There are three parts to La Rambla. Food, flowers and small birds/animals. When you reach the "top" you can take the Metro to La Sagrada Familia, the "new" cathedral. The "old" cathedral is in the Gothic Quarter, where it's fun just to wander around. Just don't do any alleys.
Also make sure that your purse is secure at all times. Serious money should be stored in the hotel's safe or in your bra. The "gypsies" are a slight problem. I was jostled by an older fellow who appeared to be drunk and if Missy has not been a couple of steps behind me and screamed, his disciple was headed for my gold chain.
Highly recommend "4 Cats" as a dinner spot. The pate's were world-class.
The architecture of Antoni Gaudi (which is the origin of the word "gaudy") is very important in Modernist Barcelona. Gaudi was the architect of La Sagrada Familia, the spires of which look like so many pizza cutters, several important buildings, and the insane Park Guell. We walked to La Sagrada Familia, got kind of lost along the way, and came across a wonderful apartment building where the pillars holding up the second floor balconies were sculptured TREES! A very fortunate getting lost.
Also, the Hospital St. Pau is grand.
Of course, I am presuming here that you share my interest in architecture. Maybe nothing could be further from the truth.
Taxis are relatively inexpensive and metered. The peseta is an annoying currency, take a calculator. There are at least two Internet Cafes on La Rambla and a gazillion places to change money. C'mon Euro Dollar!
You probably won't want to spend much time in the airport, but there are some terrific shops if you're outbound from Barcelona.
Also on La Rambla are numerous newstand kiosks. If photography isn't your thing, there are a number of beautiful books with AbFab photos to take home. I take pictures AND buy the books.
Sister-out-law and I managed to do all of the above and a bit more in barely more than 24 hours. We agreed that we could have stayed for weeks.
pamda -- CruiseMates First-Time Cruisers Editor
NOTE: English is fairly widely spoken, but the Spanish is strange. It's Catalan, not Castillian. However, if you ask, most people have Castillian.