The standard packages available in Go for creating a WebApp are net/http and html/template. There is an excellent step-by-step walk-through of creating a simple wiki using Go located here:
The golang folks have done us a great service. The wiki builds from a bare-bones web server to a primitive wiki, showing us how to effectively use redirection, templates, and a number of other concepts.
My familiarity with Go has increased as a result of this tutorial. Bravo!