First and foremost, welcome.
Second, Barca, is incredibly expensive.
First I would suggest you google rental properties available in Barca and check out the prices. The further out you are obviously the cheaper the rent will be, however, from what a friend told me recently he couldnt find anything under 550 euros and that was just for a one roomed apartment.
If you are lucky enough to find a job and I stress the IF, you will have to consider transport costs if you don't live close enough to walk to work. The metro is great, however, the cost of this has to be factored in with the rent as my friend found. The Spanish Government reckon a person can live on 650 euros a month, (excluding rent) however I think this figure is a little low as food prices are on the up as are the utilities, cost of transport etc, etc.

One thing, why Barca? What is drawing you to this city?

Unless you can speak Spanish fluently, preferably topped up with another language, other than English and have something special to offer, I would suggest now might not be the time to come over. Unemployment is a real problem and from my experience most companies prefer to give locals the work rather than foreigners unless of course it is very low paid which will of course make living in Barca very hard.

However, good luck.