On my MAC the Photoshop CS5 plugins in my plugin folder do not show in the filter menu, i.e, "lighting effects"? What am I doing wrong? Is there something I must do to install or activate them?
Welcome to the forum.
Unfortunately, you have posted to the Premiere Pro CS 5/5.5 forum. You need the Photoshop Forum.
Much will depend on the exact plug-ins. Most have their own installer, and that should be used.
You would need to run CS5 in 32-bit mode, as the Lighting Effects filter is not available in the 64-bit Mac version of Photoshop CS5.
Here's how to launch Photoshop in 32-bit mode: