Here are some suggestions from my years of Tech-Eds:

1.  Bring moleskin for your feet, and use it prophylactically, before your feet get blisters.

2.  Bring a power strip; you will make many friends in breakout sessions.

3.  Bring a decent backpack.  Sometimes the Tech-Ed backpack is good, and sometimes it is weak.  Don't gamble.

4.  When I was in New Orleans, the breakfasts were dismal, while the "special meals" folks lived high on the (figurative) hog.  So I signed up for special meals, just in case.  Not saying everyone should do this, just sharing a personal best practice.

5.  You don't necessarily have to be in the keynote hall for the keynotes; you an find a comfortable spot outside and watch it while doing other stuff.

6.  Don't fret so much about taking notes; you can download the powerpoints and session videos soon after the session itself.  Even so I often take notes to make myself pay attention.

7.  I always have a bittorrent client running for Grateful Dead and other (legal) live music torrents.  Legal though this may be, it can get your machine blacklisted from conference wifi; be sure to turn your bt client off at the convention center.

8.  Expect great things.