I go the the "Archive" place - see black line on the bottom of each page and click on it. (if you've chosen the forums you like, they will show up in red.) Choose a forum, say "Main" for eg. The new posts are in green and the ones you've read are red (makes sense!)
I also have my thread display options set to "Thread Mode" so I can see a brief list of all the replies.
Good luck!