just to clarify -
if they go on sale at 11, i would get there at 1030. no earlier. everyone gets a number, and a RANDOM number is selected as the first person let into the Garden. Therefore, every single spot in line has the same probability of being chosen.
when you get into the box office, you will have the opportunity to purchase any seats that are available, based on availability. i think there is a 4 ticket max, i am not totally sure.
in my experience i feel that the best chance is to wait in the line and once 11am rolls around, start using your cell phone in addition to being in the line. also, try and have someone at home (or work), take a shot at purchasing the tickets. buy as MANY AS YOU CAN, because if you get anything you will be lucky.
hope this helps