Connecting to one of these online catalogs really isn't very complicated - it just seems that way in comparison to what we do today. Here's an example:
 

GEORGETOWN UNIVERSITY MEDICAL CENTER
GUMEDLIB2.GEORGETOWN.EDU

DOC (Dalgren Online Catalog) is the public access catalog of The John Vinton Dahlgren Memorial Library of the Georgetown University Medical Center. It runs on Library Information System (LIS) (TM) software developed at Dahlgren, and lists the books, journals, audiovisuals, and software available in the library. THe catalog is available to the public free, 24 hours a day.

INSTRUCTIONS:
1. Telnet to gumedlib2.georgetown.edu.
2. Login as melib.
3. Enter the password dahlgren.
4. Identify yourself as netguest at the name prompt.

NO FURTHER INFORMATION IS AVAILABLE AT THIS TIME.