I'm working on a project and am attempting to add smoke to a chimney but am unable to locate it in the construction set (or click on it in the render screen). Could someone direct me to it please?

In the Activators tab.
active_chimney_smoke_02
chimney_smoke_small
Those are the main ones. The others usually have the Raven Rock scripts on them.

Remember that you can search for text on objects.
Edit->Find Text->Objects

And to click on it in the Render screen, you have to locate the pink cube at the base of the smoke.

Excellent. Thank you, Pluto