To start of to open the Command Prompt just click "Start => Run and type 'cmd'"
Basically to start off with you should open notepad and type:
What this does is essentially block the command from showing while still showing the output.
Now with batch files there are various ways to "communicate".
@echo offecho hello worldmsg * hello worldnet send * hello world
Go ahead and write that into notepad and save it as com.bat. Then double click to start.
We will be using all of them except echo as it is pretty self-explanatory.