Welcome on board. One little warning for those of you who would be using session manager plugin in your favorite browser: we are currently running on an old version of Joomla which can be a bit roguish from time to time...
In particular, if you close your browser when on a restricted area of our site/forum (registered-users-only pages), your session manager might want to re-establish your site/forum session and be violently rejected if your session has expired in the mean time. The regular behavior is to display an error page explaining the situation, but this very action might not work systematically on this old version.
It seems that such situations might create weird side-effects and it's better to avoid it: a simple click on the big NHA logo (back to homepage) or on the 'Forum' menu item (forum homepage) BEFORE closing the browser (granted your session is updated by the manager plugin on browser closing event) is the best way to avoid weird behaviors like the ones above on session restore.
Aside that, have fun!