If you arrive at the airport, the quickest and easiest to move the center of the city, option is the "Aerobus" quickly recognize him for his painted with the word AEROBUS and blue sky background airplane. Stops are at strategic points in Barcelona. Pl. Spain, Gran Via-Urgell, Pl University and works 365 days a year with departures every 5 minutes. From 5.90 €.
In your day, the Barcelona metro is the fastest option, avoiding traffic and traffic lights. There are 8 lines of Metro-TMB and 3 rail lines-FGC (Ferrocarriles de la Generalitat of Catalonia) the only difference between them is that the metro is managed by the City and the second by the Autonomous Community, but you can make transfers between them using the same ticket.
You have to keep in mind that the subway is not open 24 hours and their schedules are:
Monday to Thursday: 5: 00h - 24: 00h. Fridays and holiday eves: 5: 00h - 2: 00h.
Saturday: from 5: 00h and continued all night service. Sunday: until 24: 00h.
Holidays Weekdays: 5: 00h - 24: 00h.
Special dates: Dec. 24, 5: 00h - 23: 00h.
Nights continuous service in 2016:
Night of San Juan (from 23 to 24 June). Fiestas de Gràcia (14 to 15 August)
Fiestas de la Merce (from 23 to 24 September). New Year's Eve (December 31st to January 1)
The same ticket purchases for subway, is also valid for the tram (TRAM), the funicular of Montjuïc, commuter trains and buses daily lines.
For rates, maps, know what your best alternative public transportation from your student flat in Barcelona and for more information please consult the web: http://www.tmb.cat/en/home