This is an old (2002), but still relevant Salon article that details an editorial assistant's experiences plowing through the slush pile (the heaps of unsolicited and unagented manuscripts that fill editors' desks.)
Humor aside, the article does make an important point: don't call the publisher. Have a question regarding submitting? Look up your answer on the publisher's website. If you can't locate your answer there, write an email. Don't send anything along with your query letter (no gifts, odd or otherwise.) Make sure your query letter is plain and well-written; this is not the time to experiment with unusual fonts, paper, etc. You'll only mark yourself as an amateur if you do. Realize what you're up against, numbers-wise, and make sure that your manuscript is the best you can make it.