A good tool to have is a “writing resume.” This is arranged just like a regular resume, but only includes information about your writing. Experience comes first, with information about your best publishing credits. You include education, but concentrate on writing classes, rather than degrees, though you mention them if you have good schools. You would also list here any experience you had that would enhance your stature as a writer. I usually say that I have served as president of the Eastern Shore Writers’ Association, and that I have been an instructor for Writer's Digest Correspondence school. Include here any experience that you feel will impress the receiving editor with your credentials as a writer.
You also list “professional memberships.” PEN is good if you can get in. If not, join some other writers’ organizations: local groups, National Writer’s Club, etc. “Awards” if you have won any, and “References”. If you know any Famous Writers ask if you may use them as a reference on your resume. If not, try to pick people in a position that will speak for you, presidents of universities, officers in writers’ organizations and so on.
Include a copy with your submission, or query letter. They won't read the whole thing, but will give it a glance and be impressed by your professionalism.