Ideally, you should have one folder on your network that is Read-only to most people and contains any objects you purchase. Ours is called "KA-Office-Library"
In Archicad, click File > Library Manager. Browse to the folder location, click the folder, and then click "Add."
You will see the folder appear on the right-side of the Library Manager. Click "Done."
I almost wish Objects Online included these instructions on their site somewhere.
Tom Waltz