Buses RS-232
You have found the way to RS-232 on Buses:
HW Server - Overview of the RS-232 standard and cabling.
Keith's RS-232 Library - Documentation with download.
Quick Reference - For RS485, RS422, RS232 and RS423.
RS-232 Diagnosis Tech Bulletin From Mike Sandman - RS-232 Serial Communications is not that hard.
The RS232 Standard - A tutorial with signal names and definitions.
Serial/Rs-232 Interfacing - Detailed explanations on interfacing the serial port. Help build the largest human-edited directory on the web.