We are getting married in France, but my French is a little lacking. Google translate has been my godsend!
You can hire wedding planners if you really get stuck, but personally, If I can do it in rural France, I'm sure you will manage in Barcelona.
My tip would be to search for their version of the yellow pages online, and get translating, its easier than you think.
Good luck.
Getting married 27th June 2012!