Things to keep in mind: editors read a lot of cover letters, often all at once. Usually the editing process is done in several stages: They read the cover letters and then the manuscripts, sorting them into two (Yes/No) or three (Yes/Maybe/No) piles. Each editor will do this with a stack, and then they will all meet to discuss the merits of the Yeses and Maybes, coming to a consensus on what will be used for next months issue, what will be held for a future publication date and what will be added to the No pile.
Reading the cover letter is the first step an editor takes in deciding whether or not to publish a poem, story, or essay. It is your introduction to the work, but unlike a foreword or introductory paragraph, it doesn't need to hook, it just needs to present.
Things you will need:
-List of work(s) submitted
Firstly, we must address the editor. An acceptable method is to use the generic "Poetry Editor" format. Often, writers believe that personally addressing the Fiction Editor or Editor-in-Chief will increase their chance of standing out, showing they know a thing or two about the journal. The problem is that editors change...frequently. You might address your submission to the Fiction Editor of 2005-07, because you read an old copy of Writers Market. This doesn't look good. Or, it could be read by a new assistant editor or GTA. Reading, "Poetry Editor," reminds this editor that he is a poetry editor now. Reading, "Mr. Bret Lott," reminds him that he is not Bret Lott. Not even close.
The first paragraph should be short and sweet. List your works and get out of the way. If you can summarize the tone in a single adjective, by all means do it! (eg. "Please consider my humorous short story, "The Land of Potato Heads, or My Summer Babysitting"). However, what shouldn't be in this paragraph, at least from my perspective, is a list of authors you read and the trip you took to Italy which inspired and shaped the five line poem the editor is about to take ten seconds reading. In some ways, an overly long cover letter can become a self-parody, especially when submitting poetry or flash fiction.
I also try to keep my credentials short, sticking to the relevant publications - for instance, when submitting fiction, I don't bring up my Creative Nonfiction award, or my year doing magazine writing.
Finally, the bio. This may seem presumptuous, but really you're just saving the editor some time in the event that your piece is accepted. I like my bio to have a joke and a little personal color to it. It emphasizes my writerness, but also presents my personality, which I am marketing just as much as my work itself. (Deny this at your own risk!)
My Cover Letter: