An Introduction to Management Science: Quantitative Approaches to Decision Making, by D. Anderson, D. Sweeney, and T. Williams. Published by Thomson Learning, South Western, 2005.
This is a college-level text for the management sciences that dedicates four chapters to linear programming, providing specific examples in media selection and scheduling.
A Power-point presentation introducing the media-planning field can be found at http://www.londremarketing.com/documents/LondreMarketingConsulting-NinePs.pdf