I've in my house 7 computers and sometimes i want to send a document or any files to another computer , every time i use USB flash drive to put the files on it , then copy , paste ,,,,etc , it is a hard way to do every two days

Is there any easiest way how to share the files between all these computers on a network , also How to Set Permissions ? someone told me about sharing files but i don't know anything about it ! if someone could make it simple for me

I'm using windows 8 pro and all the other devices using windows 7 ultimate

1. navigate to "‪C:\Users"
2. right click on public then properties
3. on sharing tab click advanced sharing... tick on Share this folder and hit apply and ok
do it on all computers
then on windows 8
1. desktop/ network "bottom right"/ right click on a network currently connected into
2. click turn "Turn sharing on or off" a form will popup
3. click yes, turn on sharing etc.etc... blah blah blahh XD