how do i share files with my other computers?

Its really pretty easy. You just need to put both computers into the same Workgroup, restart, and then access the files you want. Go to Start > Settings > Control Panel > System. Check the Computer's name, you'll need to know each of these. Also on this screen, you should see the Domain name or Workgroup name. Make sure both computers have the same Workgroup name. Make a change and restart if needed. After the restart, to access the remote computer, go to Start > Run, type \\computername\c$ and hit enter. Now you're looking at the C drive of the remote computer. From here, just browse to the folder you want, and find your files. If you need to get to D, or E, or any other drive letter, type \\computername\d$ or \\computername\e$, whatever one it is you're trying to get to.

Enable media sharing in WMP, or use another program like VLC.