There a five page article in the back of every copy of Death Sentence called The Guide to Making Comics. In total it's about 17,000 words covering everything you need to know to get a comic made. Here's a little excerpt from issue 2.
"With dialogue, people rarely ever say exactly how they feel. They’re obtuse; they don’t want to admit things to themselves, or to others. They might think one thing, but say another. They might joke when they’re scared, or feign concern when they’re amused. We’re all attuned to picking up on the nuances of a discussion, the double meanings, irony, and body language people might use to finesse their conversation. Dialogue that doesn’t reflect that sounds unnatural. The language processing regions of the brain need something complex to keep them stimulated. So trust the reader to decipher the subtext. They’re brighter than you think."
Issue 2 discusses plotting, writing and art. It's available from your local comic shop or as a digital download: http://www.comixology.com/Death-Sentence-2-of-6/digital-comic/50420 .