RS232 is a standard for serial connections. In theory there are two ends to a RS232 connection a DTE and a DCE.
RS232 uses pin 7 for ground, and pin's 2 and 3 for transmit and recieve. Other pins are used for hardware flow control, Ring indication etc.
RS232 requires you to select a transmit/receieve rate called a baud rate. "Standard" PC's support up to 115200 baud. Almost everything defaults to 9600 (although not always).
It doesn't matter what baud rate you choose, if it's not plugged in
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