In my opinion the easiest way to share files between computers in a simple home network is by using an ftp transporter. To exchange files you need a server (file source) and a client (file receiver). Either or both can be installed on any computer. My favorite Linux ftp client is Filezilla, which is very fast and reliable. I like vsftpd as my server program.
(1) Install vsftpd on your server computers and filezilla (or equivalent ftp client) on your client computers.
(2) On your servers, configure /etc/vsftpd.conf by simply erasing, as root, the pound sign (#) before the processes that you want enabled. I enable:
local_enable=yes
write_enable=yes.
(3) Reboot, or simply reload vsftpd:
sudo /etc/init.d/vsftpd restart .
(4) For a client to receive files, the address of the server is needed for the client's ftp program (filezilla). To get the addresses associated with a server (computer) put the following in the terminal of the server computer:
sudo ifconfig -a.
If your system is wireless, then the address you want is the wlan (or wlan0, wlan1, ...) inet addr. It will look something like 192.122.1.37. If you are on a wired system, it is probably the lo inet addr that you want, and it will be a similar expression.
(5) On the client computers configure the ftp transporter (Filezilla) as follows:
Host: Address found in (4).
Username: Name you use to boot into the server.
Password: Password you use to boot into the server.
Port: "Ignore".
Click the quickconnect or connect button. The files in the server should appear in the ftp's server domain.
(6) If above is unsuccessful, the likely culprit is the firewall on the server. To disable it: sudo ufw disable. Retry (5). If now successful, then reconfigure the server's firewall to allow messages from the client's address, or just leave the firewall off.