please go thro mailing list guidelines
http://demo.ilugc.in/content/mailinglist-guidelines - sply - #1, #5, #6
Also, you may have to learn how to do a job posting,
http://www.resortjobs.com/employers/quickpost/tips.html
http://entrepreneurs.suite101.com/article.cfm/how_to_write_a_job_posting
http://www.recruitersnetwork.com/whitepapers/effectiveads.htm