None of Your Business

Here is some more discussion about NONE.

Dr. Lewis checked out one of his favorite books on grammar -- “Woe is I” -- on “none.”
The author, Patricia O’Conner suggests that “none” is usually plural. She offers this guidance, which is verbatim from page 28:

• If it suggests “none of them,” it’s plural: None of the fans are fighting. None are excited enough.
• If it means “none of it,” it’s singular: None of the bout was seen in Pittsburgh. None was worth broadcasting.

That seems to be the rule (or guide) I have usually worked from and that you should follow.

In addition, The American Heritage® Book of English Usage: A Practical and Authoritative Guide to Contemporary English, supports this guidance.
By the way, this is another free grammar book online available at: http://www.bartleby.com/64/

None

“… and then there were none.” The closing words of this well-known nursery rhyme should dispel the notion that none can only take a singular verb. People opposing the plural use base their argument on the fact that none comes from the Old English word an, meaning “one.”

But the citational evidence against restricting none is overwhelming. None has been used as both a singular and plural pronoun since the ninth century. The plural usage appears in the King James Bible as well as the works of John Dryden and Edmund Burke and is widespread in the works of respected writers today.

Of course, the singular usage is perfectly acceptable. Whether you should choose a singular or plural verb depends on the effect you want. You can use either a singular or a plural verb in a sentence such as None of the conspirators has (or have) been brought to trial.

However, none can only be plural when used in sentences such as None but his most loyal supporters believe (not believes) his story.