first off, GL and have fun. Live tournaments are great.
Now, advice:
1) Look for "internet pros". These guys can't handle chips and cards very well but MAY be able to play. Consider them normal players until proven otherwise.
2) Be sure to count the pot, even when you're not in the hand. It's important to see who wants to play big pots early.
3) Expect to see better hands shown down live than online (embarrasment factor). Stay aggressive on the turn if you think you have the best hand, make them pay to draw.
4) Expect the level of play to coincide with a $5.50 online tournament. You are going to run into a LOT of donkeys with a few VERY good players.
5) Decide how you are going to rebuy before you sit down. Personally, I'd take 5x buyins, rebuy before the cards are in the air, be prepared to double-buy again if neccesary and nearly always take the addon unless you are obviously WAY ahead of most players, probably 1st or 2nd.
again, GL and have fun!
edit: oh yeah:
6) Read hands ESPECIALLY when you're not in the hand. Put people on ranges and types of hands. The ones you can't read are either better than you or complete donkeys. Make an educated guess as to which
