Here is a quick tutorial about customizing a single node in Drupal. There are many reasons you want to customize a node, could be a sponsors page, a product you are promoting, a splash page, just a few examples. You can see a working example of a node already customized here.
Our goal here is to remove the top part of the page, the left and side parts of the page. You can also remove bottom part of the page if you like. The node can be fully customized. At the end, you are left with just the page content.
I used the fusion theme in this example, you can achieve the same thing with any other theme.
1 - First create a page/story, or if you have one already, find its node ID(node/NODENUMBER)
2 - Open the file page.tpl.php
3 - Save It As page-node-NODENUMBER.tpl.php
4 - Remove the header Divs/header content
4 - Remove the left and right sidebars, in the Zen theme, they are called sidebar_first, sidebar_second. Remove the footer if you like.
Once you have modified the node, upload it to your current active theme. Then go to Site Configuration > Performance. Clear the cache.
Now go to the customized node. Just the content of the node shold be displayed. If it looks messed up - things are out of place, that means you have removed too much. Undo the changes, re-upload it. Keep modifying the template until you are happy with the results.
The Zen theme is easier to work with, I recommend it.