MediaJobs.net
Online job board with over 15,000 media jobs, including jobs in media, marketing, advertising, and public relations, with free job searching and resume posting for job seekers.
http://www.mediajobs.net/

The Biz
Search for jobs, build a career network, and connect with the hiring team at the companies you want to work for. Allows entertainment and media professionals and enthusiasts to connect with colleagues and peers, search for jobs, recruit talent and exchange ideas.
http://thebiz.variety.com/