If you're going to be creating or modifying a WordPress theme, it pays to start with the basics. That's what this chapter is all about. By reviewing the recipes contained within, you'll learn how to find useful documentation, how to download and install themes from various places, and what is required if you want to create your own theme from scratch.
As you progress through the recipes in this book, you'll need a theme to work with. If you're an experienced WordPress developer, you'll probably want to create your own theme by using the recipe Creating a theme from scratch contained later in this chapter. If you're just starting out, I recommend using either of the two themes distributed with the base install of WordPress. Both "WordPress Default" and "WordPress Classic" offer solid bases on which you can build your custom theme.