The add-on puts a small monkey icon in the bottom right corner, from where you can add new scripts and manage the ones you’ve already installed. Other than that, it doesn’t include any configuration options.
The first time you launch Greasemonkey you’re presented with an introductory website which contains basic information and a link to Userscripts, where you can download scripts. Be sure to bookmark this site, as Greasemonkey doesn’t include a link to it anywhere.
Of course, you can also create your own scripts and use them with Greasemonkey, but that requires coding knowledge.
With Greasemonkey you can use hundreds of scripts to change the way popular websites look and behave. Download Greasemonkey