At some point in this game it becomes necessary to write query letters to agents and/or publishers. Have any of you written a query letter in the past? What are the most important elements of such a letter.
Ditto–regardless of what type of submission it is. The average submission may not get read past the first page… but you want to at least get the editor that far! A cover or query letter that doesn't follow the market's guidelines will get you a rejection letter if you're lucky; just as likely it'll get your submission circular-filed (why should they bother responding to you if you can't be bothered to follow a couple simple rules?). The most important of these rules being send it to the correct person: make sure you have the most recent information possible, as editors change all the time. Send it to the wrong person, and it's all but guaranteed to end up circular-filed. (I normally put the relevant position, e.g. "fiction editor," below the name on the envelope, so that it can be redirected easily in the face of any recent, unannounced changes. As mean as I might make editors and publishers sound, they really are willing to meet you halfway as long as you've clearly made an effort to meet their needs. Usually.)
As to specifics for query letters, I can only repeat what I've read in professional sources, since I have yet to submit anything anywhere that was of sufficient length to require one. One page; first paragraph should specify what it is you're submitting (e.g. a fantasy novel of X-thousand words); second paragraph should provide enough of a synopsis that the editor can tell where you're taking it and how it might differ enough from titles already in print that it's worth taking a chance on; third paragraph, brief bio, including relevant publication history if any; sign it, send it.
There's another thread around here somewhere about writing synopses; some relevant information appears there as well.
Query letters are an art in and of themselves.
(Coming out of hiding for this one)
The purpose of the query letter is to get the editor (usually an acquisitions editor, but I know many EICs who read slush submissions along with their associates) to put down the letter and want the work NOW.
Always follow the guidelines for query found on the publisher's site. Also, remember that "Show, Don't Tell" is the golden rule of queries. Editors want to know -how- the character reacts, they want to see her in action and feel what she feels. In my experience, queries are like poetry in that you want to pack as much of the novel's draw as you can into as few words as possible.
This is a great site for query information. I'd -highly- suggest reading through the examples provided before sending to an editor (or agent, if you're going that route with larger works). The query is your chance to get your foot in the door. After that, your work will speak for itself.
And avoid -all- the "nifty" things that amateur writers do when submitting queries:
Don't send paper queries with funky colors or drawings.
Don't send emails containing animated GIFs or (*shudder*) music.
Don't attempt to send any sort of gift or renumeration -at all-!
On the other side of the coin... threats don't work and the query is -not- the place to list your background (and certainly not to try to 'explain' any checkered past that you may have).
From what I've heard, they are looking for your voice, or the narrator's or character's voice, to shine through. Follow the publisher/agent guidelines and the basic three paragraph set-up but there is, and it is necessary, that you make it your own.
AW's a really harsh place. You'll get a lot professional, unprofessional, helpful, unhelpful and very, very raw advice. No one sugar coats everything over there. You don't have to take all the advice of course, but it's a great place to get lots of opinions, and then see which ones make sense, and which ones agree.
The main thing I've learned from writing query letters, aside the excellent advice given in the other posts is this: Make it short. Like 2-300 words. Maybe 500 if you've got an impressive resume. You're trying to sell the manuscript, not tell the whole story. If it's full of background details, the agent's not going to read it anyway.