or while on any thread or heading, right under your name is a link that says "show unread posts since last visit" if you click on that link, it will show you all the threads you have not read yet and you can pick from there the ones you want to read. Once you have viewed them all, then you can go to the right side where the button is that says " mark all messages as read" click on it, then you wont have to wade through all the sections,, or all the unread threads to find new ones you WANT to read.
as an aside, if you want to find answers to threads you have written in, there is another link to sort by "show new replies to your posts" which will sort out and show you unread answers to YOUR posts.
You can also go under "additional options" the same link to add pictures,, and there is a check box to select "notify me of replies" and you will get an email whenever an additional post goes onto that thread thus saving you from doing any searching for those answers,,,
have fun!