Drupal theming

As example, we have 2 content types: page and story

Create new theme and define regions in its info file:

regions[left] = Left sidebar
regions[right] = Right sidebar
regions[content] = Content
regions[header] = Header
regions[footer] = Footer
regions[pageright] = Page right
regions[pagetop] = Page top
regions[pagebottom] = Page bottom
regions[pageleft] = Page left
regions[storyright] = Story right
regions[storytop] = Story top
regions[storybottom] = Story bottom
regions[storyleft] = Story left

Then in template.php add

function THEMENAME_preprocess_node(&$variables) {
    if($variables['type'] == 'page') {
        $variables['pagetop'] = theme('blocks', 'pagetop');
    }
}

Then create files node-page.tpl.php and node-story.tpl.php and insert in them somethins like this:

<?php if ($pagetop): ?>
<div style="background:#999;padding:1em;">
    <?php print $pagetop ?>
</div>
<?php endif; ?>

Imagecache: dynamic image manipulation

Theming CCK fields within a content type