It's been awhile since I used it but try this:
On the bottom left corner of a page of a thread there is a "Favorite Thread! (toggle)" option. If you click on that (one time), it'll make it a "favorite thread" that is then available and seen in your "My Home". If you click on it a 2nd time, it'll remove it from your favorites.
You can then go into your "My Home" and see the threads.
If you go into "Subscribe / Unsubscribe from receiving forum posts by email, change message notifications, etc" at the bottom of your "My Home", you can also set the indicator on that will e-mail you every reply to a thread you've setup as a favorite. It's been awhile, but I think the text of the new post also shows up in the e-mail so you can read it right from there.