Read this recent thread in its entirety (click below). Click on the links that I and others provided, and then come back to this thread with any other questions you might have. I understand that modes are confusing (and that there's a lot of misleading and simplistic info out there also) , but comprehensive explanations are available - the zentao site is one of them.
http://www.guitartricks.com/forum/showthread.php?threadid=6513&pagenumber=1