The "Join chapter" link for New Jersey has been fixed, and is now working thanks to Eric (Torque1st).
To "officially" join and have it show up in your user profile that you are a member, simply scroll down to the New Jersey chapter on the main forums page. There is a "Join chapter" link directly under the words "New Jersey Chapter".
As for the list of chapters you see when you click on the "Chapters" link at the top right of the page, Ken (Webmaster) is the only one who can add/fix those links. He is aware that we are missing, and it is on his to-do list.