Hi there,
I stayed in a hotel called hotel Icaria which is a little bit outside of the city and walking distance from the beach which I loved. It has a pool, nice restaurant and it is a lovely hotel. It is on a good bus route and is close to the metro too. The city centre is about 20 mins on the bus. There are loads of nice restaurants around too. Its close to the Olympic Village and the beach and surrounding area is fab.
This is their website [broken link removed] but I think it might be worth your while booking via bookings.com or 1800hotels.ie etc
Enjoy Barca! It's a great holiday destination....