Since this is relevant, and since I've seen far too many new (and
old) authors make mistakes in this area, I decided to post this to
the list as well. 

Now, the question at hand was, what is the correct punctuation in the
following examples...

#1  "We were only after Ranma this time, but since you came along

as

well, we can train you too!"  Rumbled the man to the little black
piglet. 

The punctuation is correct, but "rumbled" should not be capitalized.

#2  "I thought the duel didn't start until noon?  It is barely 
eleven!"  Snarled Shoki.

Again, capitalization. The author shouldn't capitalize "snarled" in
this example. 

As for the punctuation, it's nearly correct...

"I thought the duel didn't start until noon" is a statement, not a
question. Also, this example could stand a contraction in the second
sentence to make the dialogue flow more smoothly:

"I thought the duel didn't start until noon. It's barely eleven!"
snarled Shoki.

#3  "You are not Ranma!  Who are you!"  He roared.

And here we have one of my pet peeves: a question not ending in a
question mark. 

In Japanese, and in some other languages, you can get away with this,
because the language has special inflections/particles for
interrogative statements. However, in English, the punctuation
identifies a statement as a question. Before you tack a punctuation
mark at the end of a sentence flatulently, ask yourself: is this a
simple statement, an exclamation, a question, or an exclaimed
question? 

A simple statement would end in: . 
An exclamation ends in: !
A question ends in: ?
An exclaimed question usually ends in: !? (Note: an exclaimed
question should only be used when the speaker is shouting. Otherwise,
a simple question mark will suffice.) 

In the above example, the sentence should read:

"You are not Ranma! Who are you!?" he roared. 

"You are not Ranma! Who are you!" he roared.

Since the above line is a complete sentence, shouldn't the 'h' be

in 

lowercase? 

Yes, but you missed the punctuation. Again, questions end in question
marks.

I've looked through the Prentice Hall Reference Guide to Grammar

and 

Usage by Muriel Harris (1992 edition), and although I could not

find 

a definite answer, I found something close. Here is what the guide 
stated:

[p. 110, Section 26b]

"Did Henry ever pay back that loan?" she wondered.

In the above example, 'she' is in lowercase. 

That's correct. However, I suggest you read the punctuation section
of the book as well, to get an idea of how and how not to use
punctuation.

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