I'm new to javascipt and need a little help/advise as to what to do. Here's what I would like to achive:

I'm not sure how this works, or even if it's javascript so please bare with me ^^
I am wanting the navigation on the right to stay on the same page, but change the description and image on the left.

For each slide I want the description to change as this is a website which will provide step-by-step guidance.

The image will open up in a larger lightbox when you click on it.

Could anybody tell me how I would implement what I've just described?

Thank you,
Oliver