How do I import / paste into libary in storyboard pro? Can I import jpgs into libary?

Depends on what you’re copying…

If it’s a layer of a panel, you just need to drag it into the library window on the right side after having previously selected the library you wish to save it to. You will know you have done this right if it offers to name/rename the template.

If you want to import straight into a library, select that library and in the left-hand window of the library right-click and select the option “Import Files…”