When you post a note it automatically will leave a notification for your friends. You don't have to do anything.
Yes, one can subscribe to other people's notes, but it's kinda not through facebook. Well it is... and it isn't. Basically, it's through RSS Feeds AND Facebook. In order to subscribe, one must go to the person whose notes they want to subscribe to's page and click on one of their notes. Once there, one must click on the blue tab that says "INSERT NAME HERE's Notes" Once there, in the right mini-sidebar there should be an option, pretty much at the bottom, that says "Subscribe to these Notes" followed by an RSS Symbol (Currently blue) and a link that says "INSERT NAME HERE's Notes." Click it. At the top of the new page there is a yellow box with some words and a link at the bottom that says "Subscribe to this Feed." Click that. A box will pop up, fill in your personal preferences, however if you've never used RSS feeds before then just click Subscribe. The page will refresh itself. If you click on where you're "favorites" appear in a sidebar of your internet exploror there should be an option next to it that says "feeds" and there you go. They'll still have to click on it yourself for updates though.