reading and writing to a serial port thru C or C++

i'm currently trying to read and write a stream of either integers or chars into a device plugged in a serial port.
i know that linux has a device for it under /dev

i tried using the standard open() to open that device but it doesn't seem to be doing anything.
my question is, how do you communicate with a serial port?

any snippet will be of great help,

thanks in advance, i really appreciate any help