Create Pligg Template
1. Add your template to templates/templates.tpl:

<a href = "{$URL_settemplate, "xxx"}">xxx</a><br/>

2. Create a new directory for your template in the templates directory.
3. Copy the content of yget(the default pligg template) into the new directory.
4. Hack the template code.

The Important Template Files
Edit these most important template files can quickly customize your site:
css/main.css : the style definition of your site.
pligg.tpl : the framework for the page.
header.tpl : header for all page.
sidebar.tpl : sidebar for all page.
index_center.tpl : content of home page.
footer.tpl : footer for all page.
sidebar_modules/ : contain templates for sidebar blocks.