Kashu, on the top of each thread there are buttons to press for "Bookmark" or "Subscribe". If you just want to be able to find posts after yours, bookmark the thread. It will appear in the "Bookmarks" section under "My Account", and once a new post is made, there will be a little image to the left of the thread title. Clicking on that image will bring you directly to the first unread post.
Subscribe does all of the above, and sends you an email notification whenever there's a new post in a subscribed thread. So if you subscribe to a lot of threads, you'll get a lot of emails about new posts. (I tend to stick with bookmark for everything except my personal thread, because I don't really need email notifications about every post in a thread I visit regularly, especially if I'm posting in it right then

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