In each forum (and on the foum index page), there is a link labeled for "marking" the the forum(s). Doing so will allow you to immediately see new posts, as their icons will then be colored, while the "marked" topics will be greayed out. This is pretty much a standard way of keeping track of topics with recent activity and with new topics. In addition, any time a given topic (thread) has a post added to it, the topic is bumped to the top of that forum's topic list. This makes the topic easy to spot as well.
Any registered user can take advantage of the topic/forum marking feature. This is designed to make it easy to separate new topics or topics with new posts from the rest of the threads listed. If a registered user wants to, it is even possible to "flag" a given topic for closer attention by clicking the "watch this topic for replies" link at the bottom. It is also possible to change the sort order for replies within a topic if you want to do so...