We stayed at the Marriott by the airport that has shuttles going into Barcelona and it worked out well for us. It is a very nice hotel and has great breakfast. While in Barcelona - you can take tours there once you are in the city. There are two tours that divide the city in half and you can accomplish quite a bit with both. If you want something low key, try Sitges. We took a bus from the aiport there. It is a resort area and it was beautiful!