Arthur A. Levine Books is now accepting submissions. Submissions of what? Well here's a list of what they're accepting:

Picture Books: Query letter + the full text

Novels: Query letter + the first two chapters + synopsis

Other: Query letter + 10-page sample + synopsis/proposal

Illustration: Three sample illustrations and/or links to online portfolios

Before you write a query letter to them, it is advised that you look at a few of their previously published books to determine whether they're the right kind of publisher for your book (they've published from J.K Rowling if that catches your interest).

Arthur A. Levine Books publishes hardcover literary fiction and nonfiction for children and teenagers (and discerning adults). They look for strong writing, beautiful artwork, authentic emotion, and ideas or perspectives that haven't been seen before. As a plus, they do fancy working with new authors and illustrators making their debut.

So, if you've had a look at their list (link will be in comments) and believe your work and their publishing style are a match, then go for it. Write them a query letter.

P.s, if you've never written a query letter before, keep reading lol. A query letter is a one-page description of your manuscript that highlights its strengths and captures the potential publisher's  interest. Basically, what is your manuscript about? Why would a reader turn to your book? What makes it original or memorable? Try to answer these questions in a way that reveals the character of your writing and gives the overall feel of the manuscript. Often good queries sound like jacket copy (ie the text on the inside front flap or back cover of a book, or the descriptions found in publishers' catalogs.)

Do NOT think of a query as a form to fill out; your letter should be as individual as the book it describes and the author it introduces. It should have your voice or the voice of your story. Consider it an opportunity to make an impression, to introduce your work to readers who might enjoy it. And don't forget to proofread your letter thoroughly before sending it! 

Now, to submit your query letter to Arthur A. Levine Books, please follow the instructions on the link in the comments below.

P.s.s If you get a message saying, "There are presently no open calls for submissions," that means they've reached their monthly limit on queries. In that case, just wait until the first day of the next month to submit your query. 

Oh and one downside in all this, they aim to respond to all queries within SIX MONTHS, so have patience.

A few more guidelines from their website:

We ask that each author send only one query at a time. Once you have received a response from us, you may send another query if you wish. We ask this only so that we may give as many authors as possible the chance to have their work reviewed. If one person sends in five queries at once, it delays the process for others. Choose the one you feel is your best work, and most likely to fit our list.

All manuscripts should be double-spaced with standard formatting. (i.e. no wacky fonts, or giant margins, etc.) Please limit your synopsis to one page.

At this time, we are only able to evaluate manuscripts written in English. If your book has been published in a foreign language and you would like it to be considered at Arthur A. Levine Books, please speak with your foreign publisher; they will know how to reach us.

While we wish we could respond personally to all queries, time constraints necessitate a standard response letter if we choose not to pursue your manuscript. However, please be assured that we do read and carefully consider all queries we receive. We will send you a response unless you’ve indicated in your query letter that a response is only necessary if we’re interested.

If you are submitting a picture book dummy (full text and illustrations), it may be sent to us through the mail. (This is the only kind of query that will be accepted through the mail.) Please send your dummy and query letter to Arthur A. Levine Books, 557 Broadway, New York, NY 10012. If you would like to receive a response, include a self-addressed, stamped envelope. If you would like your dummy to be returned to you, be sure to include enough postage to cover its return.

Thank you again for your interest in our imprint. We look forward to reading your work!