Yes there is a way to set your notifications. Go to the user CP link in the upper left hand side of the page. Under "Settings and Options" go to "edit options".
Under "Messaging and Notification" you can set your subscription preferences.
If you don't want to set it that way for all threads automatically, you can do it manually in each thread you want to subscribe to by going to "Thread Tools" at the upper right of the thread and clicking on "subscribe to this thread"