First time
There's a charming piece in Holly Lisle's Vision called "My First Time," about an author going through the process of submitting a story (to us!) for the first time. I totally sympathize with the sentiments expressed in that piece; it's humor of familiarity.
I think this would be a good time for me to issue one of my periodic comments that we're not total sticklers for exact precise formatting; we've never rejected a story on formatting grounds. The closer the formatting is to our preferred format, the easier it is for us to read, but mistakes and variations will not ruin a story's chances.
In general, I think what most editors care most about is readability; the main reasons for both standard formats and specified nonstandard formats is to make the stories as easy as possible for the editor to read.
I'm particularly sympathetic to email formatting issues, because it's hard to guarantee that the recipient of the mail will see anything resembling the same format that you see. In fact, our formatting guidelines are mostly aimed at trying to make sure that we see the same format you see; if you send us a story formatted in some other way, chances are good that it'll get garbled in any of a variety of ways, thus making the story less readable to us even though it looked fine to you.