Question of manners in Spain
I have a question of etiquette for those of you from Spain or familiar with Spanish culture.
Next week my roommate and I are having a party for my 50th birthday. Some of the Spanish friends that I have invited have offered to bring something: beer, vine, food, etc. Is it polite to (graciously) accept the offer? I know that in some cultures it might be rude not to accept, but I don't want to accept if that is seen as taking advantage of someone. Should I instead politely decline instead unless they strongly insist? Is there an equivalent of "Oh, please don't go to any trouble?" Oh, help! 
4 Answers
In my experience, how this is handled depends on what kind of party you're having.
For an informal, "buddies" kind of party, it's certainly fine - and great!- to accept whatever people want to bring. "Yeah, dude - whatever you want to bring along is fine, thanks!"
For a formal affair, you're supposed to have everything taken care of, and in that case it is appropriate to say: "Oh, that's not necessary, thank you - just come along". Then your guest will probably bring a bottle of wine or liquor, or maybe some dessert anyway, because it's rude to go to a party empty-handed.
I think you should accept it. Don´t worry, they won´t think that you are taking advantage of someone. I mean, if the party is in your house it's like: If you put the house, we put the wine.
Definitely, accept that, because it's natural. You are not taking advantage, because everybody knows that giving a party is a lot of work. You will probably have to wash the dishes 
Happy birthday! Enjoy the party!
In my experience, people bring something whether asked or not. Wine, dessert or flowers. Just like in the U.S.
