Help on making a port listener application

Hey, I'm trying to make an application that will run on a specified port (For example port 24432) then with a client application i can connect to that port and send info to it...

For exapmle.... say I have the server application and i want any incoming text to be sent to a list box i would recieve it on an incoming winsock or something through that port and then put it in the list box....

I honestly have no clue whatsoever how i would do this. I'm very new to networking. Please help. thanks!