where is the sold out button generated in zen cart?

includes/functions/functions_general.php

How do I replace the "... more info" text.

This is under includes/languages/english.php

The line you want is...

// more info in place of buy now
define('MORE_INFO_TEXT','...more info');

Which file creates the "featured products" section?

this is saved here...
includes/modules/featured_products.php

the prices are pulled out here...
includes/functions/functions_prices.php

How do I insert a category image using the zen_image() function

<?php
$categories_image = zen_get_categories_image(1);
echo zen_image(DIR_WS_IMAGES . $categories_image, $categories->fields['categories_name'], SUBCATEGORY_IMAGE_WIDTH, SUBCATEGORY_IMAGE_HEIGHT);

?>



changing the '1' in zen_get_categories_image(1) to the category id

How do I reference the row or column of a category in the category list, with css.

The category list is generated in the file includes/modules/category_row.php

If you change the line starting $list_box_contents[$row][$col] to

$list_box_contents[$row][$col] = array('params' => 'class="categoryListBoxContents"' . ' ' . '', 'text' => '<div class="categorybox colbox'.$col.' rowbox'.$row.'"><a href="' . zen_href_link(FILENAME_DEFAULT, $cPath_new) . '"><span class="categoryimage">' . zen_image(DIR_WS_IMAGES . $categories->fields['categories_image'], $categories->fields['categories_name'], SUBCATEGORY_IMAGE_WIDTH, SUBCATEGORY_IMAGE_HEIGHT) . '</span><span class="categorynamex">' . $categories->fields['categories_name'] . '</span></a></div>');

Then this provides new classes to reference -
categorybox = the image and title
categoryimage = the image
categorynamex = the title

It also provides two classes which change depending on the row or column you are in.

colbox0 is applied to the category of every first column element,
colbox1 is applied to the second etc.

rowbox0, rowbox1... is the same, but with the rows.

Where do I add new colours to the colours attribute?

Under catalogue - attributes controller.

Select Values, and under that you can select the "colours" option name and enter a new one.

Where do I update the main product image size?

Under configuration - images.

This sets a maximum image size, but smaller images can be uploaded.