If there is any thread you're particularly interested in (like one you started) you can click "Receive updates to this thread" and you'll get an email anytime someone posts in that thread. This is also known as 'subscribing' to a thread.
The email has a link that will take you directly to that thread, and also a link to 'unsubscribe' to that thread or all threads.
This will not work for entire forums, just for threads within a forum.
Of particular use is the "Updates" thread in the "What's New" forum. I recommend everyone subscribe to that thread.