You can follow certain pages by clicking on "follow" above the commenting box and unfollow it by clicking on the "x."

Once you follow a page, you'll be alerted by email whenever someone posts on it. This can be useful if you want to follow a conversation or stream or if you want to keep track of RSVPs on an event page. 

Note: When you create a page yourself (such as an event or a suggestion) you'll automatically be following that page. To unfollow it, see instructions above.