Grammar Question

[pbmn]

*I've never asked nor answered a question based on grammar before, so I'm not entirely certain on where to put this thread. If it's in the wrong section, please move it.*

I was wondering what the punctuation was in a sentence like: "What are you thinking about(?)" asked Amy. Do I put a comma there like in any other dialogue sentence, or do I add a question mark without a comma, or both (pretty sure it's not the last, but you never know...)

I never learned this in school before, or at least don't remember, so can someone please help me? Thanks.

[Shalot]

I think you put it inside the quotation marks. If the question is part of the quotation, then the question mark goes inside the quotation marks. I do have a book on this upstairs, but I don't want to go get it. But I think that's right. What does everyone else think?

[Oniw17]

Question mark works by itself I think. That's what I would do.

[Lady Raven]

Question mark only. No need for comma.

[PeterL]

"What are you thinking about?" asked Amy.

There are several style guides online, including
The Economist
http://www.economist.com/research/StyleGuide/?CFID=1489356&CFTOKEN=61778300

and
The Elements of Style
http://www.bartleby.com/141/