I know it seems impossible to you, but it's really not that difficult.
You can use one of the free templates available for Zen Cart to get you started. Even if you decide not to use the template itself, they're great learning tools and can serve as an example of how to setup a custom template. You can see the templates in action at http://(sorry, site offline)/ and select "go to demo". Use the pull down menu to change templates and see what they'll look like on a live site.
This list is a bit outdated, but it'll give you an idea where to start to create a very basic custom template (you can build from there):
- includes/languages/YOUR_TEMPLATE/english.php
- includes/languages/english/YOUR_TEMPLATE/index.php
- includes/languages/english/YOUR_TEMPLATE/meta_tags.php
- includes/languages/english/YOUR_TEMPLATE/header.php (to change the logo and header text)
- includes/templates/YOUR_TEMPLATE/template_info.php
- includes/templates/YOUR_TEMPLATE/common/tpl_header.php <- may not be necessary
- includes/templates/YOUR_TEMPLATE/common/tpl_footer.php <- may not be necessary
- includes/templates/YOUR_TEMPLATE/images/logo.gif (or .jpg or .png)
- includes/templates/YOUR_TEMPLATE/css/stylesheet.css
Anywhere you see a /classic/ folder, you can create a folder for your custom template. You can copy the necessary files from either the /classic/ folder, the /template_default/ folder or the parent folder.
Edit includes/templates/YOUR_TEMPLATE/template_info.php to give your template identifying information so you'll recognize it in the admin under tools->template selection.
Note: if you've changed the height of the logo in header.php, you may need to change it in your stylesheet as well:
#logoWrapper{
background-image: url(../images/header_bg.jpg);
background-repeat: repeat-x;
background-color: #ffffff;
height:75px; <-adjust this line if necessary
}