Serial port access can be very useful during embedded systems development.
I do most of my development on Mac OS X, or Ubuntu and Windows virtual machines. I use a USB to serial cable/breakout to connect a serial port to the Mac, which is then redirected by Parallels Desktop to the guest OS.
If you have a cable that uses the Prolific USB Serial chipset, getting up and running is well documented by Plugable. The driver they provide works for me. Most other cables use a chipset from FTDI, but Mac OS X already provides a driver for that.
To interact with a terminal on the embedded system you need some kind of terminal emulator.
I use miniterm.py and screen on Ubuntu
miniterm.py -b 115200 /dev/ttyUSB0
Ensure that you have access to the device
sudo chmod 777 /dev/ttyUSB0
On Mac OS X I usually use screen
screen /dev/cu.usbserial 115200