If you mean your own replies, click on "my stuff", then click on "View Post's" If you mean someone else's posts, click on their name, then click on "View Post's".
If you are interested in reading new replies to specific forums, threads, or members, you can add them to your WATCH LIST.[+] How do Watch Lists work? You can select to be notified by email when a new post is made to any of the selections on your WATCH LIST.