If I subscribe to Mac tip of the week on iTunes what can I do to automatically delete the tipS after viewing or delete after so long of a period ?

if these are emails you’re receiving, just set up a mail-rule; like move mails from that address to a specific folder and another to delete all messages in that folder that are older than f.ex. a month. Of course you could also unsubscribe if you don’t want them at all…

Yes, you can delete them after you’ve watched them. And if you haven’t watched any episodes for a long time, iTunes will suspend your subsciption until you you tell it to stay current.

The assumption is that you’ve lost interest, and there’s no point if filling your hard drive with videos you won’t watch.

I’m assuming you’re referring to a podcast subsciption.