however I was on a cruise so cannot recommend a hotel.

I can however recommend the Sagrada Familia Cathedral, stunning, just be aware half western europe is visiting it at busy times.

Picasso Museum as previously mentioned, and try the "Magic Fountain of Montjuic", (I haven't visited this myself but others did and recommended it).

I wasn't too impressed with Las Ramblas but I suppose you have to do that as well and of course you have to see Barcelona soccer team if you can, they are probably the best team in the world, packed with superstars.

Have fun,
Neil.