Greetings mmsafr,
The Galileo have pin 0 and 1 for the Serial communication, in case you want to use other pins you would have to use the software serial library and it does allow to use multiple software serial ports, but only one can receive data at a time. Unfortunately this function is not yet been implemented into the Galileo this is a post about that library (https://communities.intel.com/thread/47898) in case you want to take a look it.
Regards,
JPMontero_Intel