If you like to learn by doing or by example, these tutorials will help you get up to speed with ProcessWire quickly.
Hello WorldsIn this tutorial you will learn how to create and work with templates, fields, pages, and how to output dynamic data via your templates. By Ryan Cramer.
Introduction to the default site profileIf you've installed ProcessWire's default site profile and want a guide on how the template files work, this is for you. This tutorial also serves as a good introduction to template files in general. By Ryan Cramer.
How to structure your template filesHow to use some of the more common strategies used by developers in structuring template files. Includes pros and cons as well as extensive examples. By Ryan Cramer.
Using custom page types in ProcessWireA look at some lesser known advanced techniques that enable you to introduce new conveniences by creating custom page types. An advanced tutorial by Benjamin Milde.