Yahoo has its own styleguide out, along with some great resources for writing content for the web.
It includes everything like basic web-friendly content advice (“Write strong headlines”) to the nuances of international grammar differences:
When referring to your own or another company, use the third-person singular pronouns it and its. In the United States, a company is treated as a collective noun and requires a singular verb and a singular pronoun. Referring to a company in the plural (they, them, their, theirs) is chiefly a British convention.
At least now I can cite a slightly less stuffy reference than ALA or Chicago.