Okay, I finally found it. Under Catalogs, you have to add a catalog, then create the link to Calibre server. BTW, I had a devil of a time trying to find anywhere in the Calibre manual or on MR the exact syntax for creating a URL to one's own Calibre server. I finally fumbled from memory. (I know it's been given on the board here many times, but I couldn't find it with a search. Seems to me it ought to be on a sticky.)
In case anyone else has a similar problem, I'll put it here:
http://yourcomputer:8080
is the form for reaching the Calibre content server when you're in your own house on your own network -- where yourcomputer is the name on the local network of the computer running the server.