For introductory courses (sophomore/junior) in Digital Signal Processing and Signals and Systems. Text is useful as a self-teaching tool for anyone eager to discover more about DSP applications, multi-media signals, and MATLAB. This text is derived from "DSP First: A Multimedia Approach," published in 1997, which filled an emerging need for a new entry-level course not centered on analog circuits in the ECE curriculum. It was also successfully used in 80 universities as a core text for linear systems and beginning signal processing courses. This derivative product, "Signal Processing First" SPF] contains similar content and presentation style, but focuses on analog signal processing. Note "DSP First: A Multimedia Approach" remains in print for those who choose a digital emphasis for their introductory course.