To explore the web with Dewey Digger, choose a category of knowledge according to it's Dewey Decimal number. I clicked on 500's, and the clicked on "animal" as my search term.
Then I choose Google as the search engine I wanted to use.
This is the page of results I got:
Using Dewey Digger is a very easy way to search for information on the Internet, especially if you aren't sure how to write a search string, or aren't sure how to spell a word. You do, however, need to understand a bit about the Dewey Decimal System - you could learn that quickly by exploring the site's start page.