What sites or resources would you suggest that will help an aged ....

.....Windows guru get up to speed on the workings behind the Mavericks OS X 10.9.3 GUI?

I have a model A-1178 with 4 gigs of RAM that is going to be used for CAT on an Amateur Radio. To accomplish this, I need to edit some files in the configuration of my MBP in order to make the Serial to USB adapter work with the Apple device. I have two different devices, one is a Prolific chip based unit while, the other is a FDDI chip based unit.

My Mac Book recognizes the devices when I plug them but, they don't control the radio; it has to do with selecting the correct port. The information that I am working with starts here;

[Ham-Mac] WSJT-X

and gets specific here:

[Ham-Mac] WSJT-X SERIAL TO USB

Here is *my* problem, for 15+ years, I've been working on DOS based Windows products and using Cisco CLI to subnet and route packets around the world but, I am unsteady with the use of the programming language under the Apple GUI. I kinda need a tutorial on the "Tree structure" and how to get into it to make the changes. I am familiar with the Terminal program but, just not sure which way to the top of the tree and which way to the root.

If, I could get in there, I could give you more info on the tty/dev...."yada-yada" , that what I am asking for help with.

.

That isn't a "programming language" it's actually a 'shell' called Bash.
This might help. If you have specific questions you can try here.
BASH Programming - Introduction HOW-TO
List of Bash online-tutorials [Bash Hackers Wiki]