Randall Rensch, Marketing Communication Concepts and Copywriting 

You know how to sell people on products.
But how do you sell someone on you?

How to Put Your Book Together and Get a Job in Advertising (Newly Revised Edition), by Maxine Paetro.
    If you're a budding copywriter or art director preparing your first portfolio, or want to improve yours, you need guidance like this paperback provides. By the way, by "book" and "portfolio," these days we mean your website. Written by a former bigtime creative department administrator, and now in its fourth edition, this very frank guide explains what a "professional" book consists of (even if you don't have produced work yet), and how to present yourself effectively. Not a generic "how to get a job" or interview-skills book... this is specifically about the ad biz. If you already work at a large agency, you probably know some of this already. But it's still a fun, inspiring read, and there are many good insights and references here for you, too.
    Not only might this book shave years off your attempts to get onto the first rung of an ad-industry ladder, it could help you decide if it's the right ladder for you.

Look at this book now.
(Also available in libraries, typically in the Career Guidance section. Be sure it's the latest edition.)