I agree with all of the previous answers, but observe that the rule may be gradually changing. In English it is becoming more common and, it appears, more accepted to pair collective nouns with a plural verb. Here is a link to a site which indicates the same thing for Spanish collective nouns: http://spanish.about.com/cs/grammar/f/collectivef.htm
So I would say that you might expect to hear and read both forms: collective noun with singlular verb and collective noun with plural verb,
but that you are probably best off following the more traditional rule:
collective noun with singular verb.