Congratulations on qualifying to represent your district. The format at the nationals (which has been revised in the last year or two) is roughly as follows: Day 1 is a full day Swiss (eight seven board matches) among the (approximately, since often one or more teams who have qualified do not go to the nationals) 25 teams in your flight, with the top 16 qualifying to play the next day; From Day 2 through Day 5, the 16 teams who qualify are drawn into a knockout bracket (seeded based on performance in the qualifying Swiss) and play full day matches (56 boards in flight C, I believe) - win and you advance, lose and you're out of the event. If you are unfortunate enough to get eliminated from the GNT, there are an assortment of events that you can play in at the nationals for the remainder of your stay. As far as preparation is concerned, try to get in as much practice as possible with your partner. You'll be playing IMPs, so best to practice that way. If possible, find a good player who might be willing to work with your partnership or team.
