you should receive notice in the mail. the information is also on the member site.
the annual dues amount per point is also available on this thread:
http://www.disboards.com/showthread.php?t=2823949
so for OKW for 2012, you will owe $5.20 per pt. you may still be able to call member administration (same number as member services, different extension) to set up a monthly draft from a U.S. checking account (which is simply the amount owed divided by 12 - no additional charges).
otherwise, you will owe the total annual dues amount by mid-january, IIRC. (i'm on the monthly plan so i'm not sure.)