Hi Adam,

If you are more interested in the design of the store, I shall assume you already have the necessary HTML/CSS knowledge (some PHP is useful) and a programmer's editor in hand.

After that, the first thing you need to do is to understand how the Template Override System in Zen Cart works.

Next, get some free templates from the Template Packages section of the downloads area. Study how the templates are implemented and play around with them.

For more advanced templating stuff (e.g. page-specific stylesheets, dynamic Javascripts), do a search in the Tutorials/FAQs section to see if someone has already covered that.

As for tools to speed things up, you might want to consider using the FireBug and Web Developer Toolbar extensions for FireFox which will greatly help in debugging your stylesheets/Javascripts.

Lastly, do take note that Zen Cart is very feature-rich and that means you will really need to spend some time to familiarize yourself with how things work/look. Patience and perseverance is key.