While reading some information on proper manuscript format on the Whidbey Island Writers alumni site, I came across the following website, and a few comments from instructor Bruce Holland Rogers, master of short fiction.

http://www.shunn.net/format/story.html

Question:  Which font should I use?

“Courier, because it is not proportionally spaced, is easier to edit than Times Roman or any other font that is meant for setting finished work.

Experienced production editors can also estimate the cast-off, or how much space the work will take up in the magazine, by looking at the pages of Courier-formatted text. A manuscript in another font is harder for them to estimate.

Yes, a lot of editing and layout is done on screens now, but many publications still use paper for manuscripts. Any manuscript you submit on paper should be printed out in Courier.

If you’re submitting to a publication that reviews the work electronically, then, sure, go ahead and use Times Roman if you want.

What the double-spaced Courier says, though, even to a publication that reviews electronic submissions, is that you are either an established professional or are a new writer who has learned what the established pros do. The standard format is like dressing your manuscript in a suit for its job interview. Some variations are like pairing a brown belt with black shoes — they may be noticed, but won’t hurt. But the farther you stray from standard format, the more likely it is that you are sending your manuscript to its job interview in a Hawaiian shirt and no pants. If your format is odd enough, the editors will know from long experience that the manuscript is probably not going to be worth their time, so they’ll start reading it in a bad frame of mind, looking for the slightest indication that the piece is as bad as they expect.”   Bruce Holland Rogers

Check out Bruce’s site:  http://www.shortshortshort.com/