Let’s write a query letter. Because the middle paragraph will be a mini synopsis for your book, I’ll go through a good way to write the first and third paragraphs sentence by sentence. Let’s start with a simple: “Dear [agent/editor’s full name],” (Optionally: Dear Mr. or Ms. [agent’s last name],)
First thing’s first, give the reason you’re writing to this particular agent/publisher: “I read on your/your agency’s website that you represent/are seeking [genre of your book] so I believe you would be a perfect match for my novel, [insert title of book] (insert word count).” As an alternative first line which is less effective but for if you lack any of this information: “I am writing in the hope of gaining representation for my [insert genre] novel, [insert title of book]. It is [insert word count] words long (optionally: and focuses on [insert key them or plot tool]).”
Now you write a mini synopsis which is how you would sell your story to a complete stranger. This can be difficult but the best way to do this is to give a summary up to a part of your novel where you think you might be able to describe the gist of the rest of you book with one or two sentences without giving away the ending (save that for the synopsis). Try to limit this to around 200 words.
The third paragraph is the bio where you need to put anything you managed to get during step 8. Size-wise it should be between your first and second paragraph and it should be in the first person. Start of with any qualifications relevant to your story or being a writer or any workshops you’ve done. Next say any awards or competitions you’ve won, and if none, talk about your passion for the genre you’ve written in. Finally give your contact information. As redundant as it seems both your cell phone number AND your email should be listed along with a “I look forward to hearing from you” if you need some filler.
Lastly you need a simple: “Yours sincerely,
[insert your full name]”
And that’s how you write a query letter. Obviously for most new writers, writing that middle paragraph is going to be the most difficult part so I would suggest looking up example query letters to get ideas about a good layout for your summary. Who knows, you might even get some better layout tips than what I’ve written here (highly likely). It shouldn’t be larger 400 words all up, no more than five paragraphs, and needless to say, spotless of errors. This will determine the fate of your story, so don’t mess it up!