There are many many reasons why I would recommend this book (421 page PDF). But what makes me link to it here is the simple introductory paragraph on page 12: "The goal of machine learning is to design general-purpose methodologies to extract valuable patterns from data... To achieve this goal, we design that are typically related to the process that generates data... Learning can be understood as a way to automatically find patterns and structure in data by optimizing the parameters of the model." Another 409 pages explaining this concept follow. Not light reading. This Reddit thread has some other suggestions as well.