I went to the draft with some friends the year we drafted T Newman. Wear some REALLY comfortable shoes because you'll be waiting in line a LONG time. Anyway, about midnight (show up at about 11:30-11:45) the night before the draft they open one of the ticket booths to give out tickets to the draft, they're free, and they will put a wrist band on you as well, I cant remember if the wristband or ticket is numbered but when you comeback in the morning there will already be a huge line, your early number should put you in the front as they are suppossed to go in order
with the number you get. I suggest you find one of the few arena security people around and check this out with him as the people who came later then you and who have waited in line for hours will want to kill you when you stroll in front of them. After that line they sort of break up the lines in to "manageable" groups which is just waiting in smaller lines inside the Garden. By the way, the guy in the Eagle costume who screeches every five seconds will drive you insane, God forbid if he is there and the Eagles won the SB.
As far as the hotel, I stayed in one right across from the Garden and could look out and see the lines forming in the morning. Sorry I cant remember the name but do a expedia.com search or something and it will be listed on there as like 7/10ths of a mile away from the Garden, it was like the first one, it was cheap for NYC like 180.00 for the three of us but it was a little crappy, not terrible but a little shabby. But the location made it worth it. Also, as for the car, they will sock you with big storage charges and good luck finding somewhere to park it on your own. The hotel hit me up for like 75.00 for just an overnight for my car.
Hope this was helpful.