I am a relative noob in tackling this, so please bear with me.

I had cloned and customized sterile-lite version of the default theme, but am stumped at how to add the jcarousel functionality to it. Enabling jcarousel on image.php for the theme didn't do anything, adding the files to the theme folder either (the only two options that my googling suggested). I do not have a working knowledge of php aside from copy pasting to include, so not sure what/where should be added, if that is what's needed to enable it. Any help greatly appreciated!

Enabling the plugin is not enough. Your theme also needs to be "ready" to use the plugin.

The Zenpage theme is setup to use jCarousel so you can see how it's done there. Look in image.php
Plugin info can be found here:
http://www.zenphoto.org/news/jcarousel_thumb_nav

In short:
Place/paste the function printjCarouselThumbNav() in your image.php where you want it to appear.
Look here for the parameters you can set in the function:
http://www.zenphoto.org/documentation/plugins/_zp-extensions---jcarousel_thumb_nav.php.html#functionprintjCarouselThumbNav

If needed, create your own jcarousel.css (to override the default jcarousel.css file) and place that into your theme folder.

Thank you fretzl, on a fresh brain and with a tiny bit of fumbling, it worked like a charm .