Barcelona is a great city you defenitely should visit! It has a lot of culture, great architecture and plenty of nice places to visit. My favorites are: Parque Güell (nice view over the city from there) and the Sagrada Familia. Barceloneta is always worth a walk. If u like to spent time at the beach, better go to La Selva (Name of the Metrostatiion near the beach), it's not so crowded, more clean and less tourists. Nightlife in Barcelona is GREAT! You souldn't miss La Champañería (near Barceloneta Metro station). If u prefer clubus and bars without too much tourists and to not spent too much money, go to the street called Aribau, it's a 10 minutes walk away from metro station diagonal. Always good parties are in the Bikini Club. If u like house/electro music, go to the pasha club. A goog bar to meet new people from all over the world as well as people from barcelona, go the Oveja negra, near the Plaça Catalunya. The easiest way to know what's going on, is when u buy the magazine called "ocio". It costs 1 euro and comes out once a week. You find in there all parties, concerts theater etc. going on in Barcelona. Good food you'll find all over the place. There's a restaurant called "la Esquinica" which is very famous among Locals, near the Metro Station Virrei Amat (blue). I personally don't like the food there that much, too much garlic... But the staff is very nice, and it's also worth to pass by just for one (or two or three...) beers. Shopping: Barcelona is a shopping Paradise!!! If u don't like the always crowded center, go to the shopping mall called La Maquinista. It's huge and you'll find there plenty of shops, as well as restaurant, bars and a cinema. I prefer it to other malls cause its open air. You get there with the red metro, station sant andreu and then a 5 minutes walk, or bus no. 11. So, go to Barcelona and enjoy this beatiful, interesting city where you never get bored! Just take careof you money, you spent it faster than you would think ;-)

I stayed in Barcelona for a week in November 2006. My friend and I rented an apartment in Las Ramblas and had a blast. If you are looking to stay up late, meet great people and drink, then this is the neighborhood for you. It's almost impossible to sleep with all the street activity, so you're forced to join in, or lie in your bed pissed off. We chose the 'join in' route and stayed up until about 6am each day. Bars are everywhere, though they are tending to get a bit trendy instead of traditional. There is a great open air market that sells fresh vegetables/ fruits, tapas, kitchen gadgets, fresh seafood, flowers, bread and cheese. we shopping there when we could and did all of our own cooking in the apartment. If you stay in Las Ramblas don't eat at the restaurants that have sidewalk tables. While it was reasonably priced, the food wasn't good, or authentic. Those were great places for sangria and beer, though. I highly recommend going onto craigslist and finding your own rental. It's much less expensive, you have your own kitchen and bathroom and you have no hotel curfews. This goes for Paris and Rome, as well. The locals were extremely friendly and gracious. We were warned about pickpocketing children, just like in every large European city, but we carried small over the shoulder/ across the chest purses that we were easily in control of. Must visit Parc Guell on the hill! We chose to walk, which was quite a trek, but we also got to see some wonderful architecture along the way. When you get to Parc Guell you will immediately appreciate it's beauty and creativity; almost dr. Seuss-like with the bonus of a great view of the city and ocean. To get the most street cred, bring skirts, pants and shoes that are in fashion. I stay away from shorts and tennis shoes. That's a total give-away and you can't blend in as a local. Pack lightly; it's pretty warm and you can hand wash your clothes without issue. It's hard to cart around two pieces of luggage on cobble stone. It is a hilly city, so be prepared for walking. They have a great transportation system, but I felt like I would miss out on something if I didn't walk everywhere. If the Picasso museum is still on display see it! I typically don't recommend spending vacation time on something you can see in a book, but this exhibit was worth it. I have been to Madrid and the Canary Islands before and didn't think much of them, but Barcelona is completely different. I would go back in a heartbeat and I would feel safe going alone. Memorize the maps and know the names of the streets before you go; reading a map in public makes you a target to unwanted children and men. Being lost is okay if you don't have an appointment. It also brings you to sites you may have overlooked. My best advise is to absorb everything; sights, sounds, scents, tastes and appreciate the relaxed approach to life.

Great food of consistent quality, impeccable service and with a 3 course menu including wine, water and a coffee to top it of, I am conviced this is by far the best deal to be found in Barcelona!
14 Euros only. Location is on the Passeig da Gracia, in the direction of pl Catalunya when coming from La Pedrera.
It`s popular with locals, but I haven`t seen any people from outside Spain there so far, strangely enough.

Restaurant POMARADA
Great food of consistent quality, impeccable service and with a 3 course menu including wine, water and a coffee to top it of for just 14 EUR, by far the best deal to be found in Barcelona!!!
Location P.de Gracia 78. *betwen La Pedrera and Pl Catalunya.

Do check out Tarragona as well.
Only 100km south of BCN and the capital of the former Roman colony on the Iberic peninsula. There`s quite a lot of impressive ruins to be seen and also some excellent museums to clarify matters a bit more.
For dinner there`s a nice place that offered a 3 course lunch, including wine, mineral water and bread for just 12 EUR!
The restaurant is called PIGAL (Carrer La Nau 6, around the corner from the archeological museum, tower and circus ruins).

For budget travelling, don't neglect the bargains at the local bodegas and mercados. Bring your own bottle to fill from giants casks in small shops all around the Barre Gothic. There's an enormous mercado along the southside of the Rambla (Mercado de San Jose). You can eat like a king for pennies.

Barcelona is a fantastic place! Go everywhere, do anything you possibly can. But one thing I will say is do try to get to the outdoor markets, they're a bit away from the main streets, but they're fantastic. You can get a lot of gorgeous locally made bags, purses and scarves, as well as beautiful jewelry and delicious fruits/olives/etc. Well worth it. And inexpensive, as I recall. 

the zoo is great to visit and the cathedral is stunning

So, Barcelona an over priced tourist trap... but I ahve to admit I really enjoyed myself there. If you are a budget traveler going through barcelona check out: http://www.barcelonavibes.com
They have a free walking tour that is wicked good. I mean you pitch the girl who gave it a few euros or what not but if for some reason you didn't like it you wouldn't have to pay for it. They ahve cooking and dancing classes. They also have very nice bikes for rental and they will totally help you figure out where would be some nice places to take the bikes to... I say bike all along the coast. So, lovely. Also, anything you do with them they will give you a free beer.... it is ass water beer... but if you aren't picky(like your the type of person who will drink Bud light or something like it) than you will enjoy a free beer.  If you like local beers get a Moritz, nice local beer that was gone for a while but now has come back. 

If you stay for more than one day, buy your metro ticket in the tourism office, not in the metro station!! A 2-days ticket (only available at the tourism office) costs half the price of a 1-day ticket in a station..