Hi frant52,
Thanks for visiting Apple Support Communities.
If you have set up Home Sharing but cannot share files between your computers, you may find this article helpful:
Troubleshooting Home Sharing
http://support.apple.com/kb/TS2972
If you would like purchases made in iTunes to download to all of your computers and devices, be sure that you've enabled Automatic Downloads:
iTunes Store: How to enable Automatic Downloads
http://support.apple.com/kb/HT4539
Cheers,
Jeremy