This article is really hilarious. For you writers out there. Just remember that it is not your job to worry about things like these. Grammar is not your job, but it is this guy's job so I thought it was a funny example of how editors can get flustered by the most minute details, while the writer is almost certainly wrapped up in the big picture. As writers, we all have common mistakes we make, this is one man who cannot stand it.
This page is great and very informative about making interesting and lasting characters that will surely add to your already well thought out story.