If you are changing planes during your trip, be sure to go directly to the next gate as soon as you arrive. Do NOT wait until the last minute, if you can help it, to get to that gate, because they WILL search you very thoroughly - part and parcel of the policies enacted since 9/11.
Some thoughts/suggestions:
1) Pack as simply as possible, as a general rule of thumb. If you are wearing a coat or jacket on the plane, be prepared to take it off and put it in the bin that goes through the X-ray machine.
2) If you can print out your boarding pass via the airline's website (typically within 12 hours of the departure time), that would be a helpful thing to speed along the process. Keep your photo ID and itinerary/boarding pass handy at all times to go through the various checkpoints - to check bags and/or to get your boarding pass issued, you will have to present your photo ID and your e-ticket/printed receipt or paper ticket.
2a) Similarly if you need to check through a bag, curbside check-in is your best bet. The skycap will ask you for your ID and your itinerary/e-ticket printout. The skycap will also issue you your boarding pass (should you not have pre-printed your boarding pass at home via the internet before heading to the airport). At the same time the skycap gives you your boarding pass, he/she will instruct you as to what gate you are to go to to catch your plane. It IS appropriate to tip the skycap $1 per bag being checked.
3) It's OK to bring food/drink onto the plane, but you're probably going to want to buy it before you get to the terminal where the prices are typically sky-high ;-).
4) I'm a gum chewer on planes - helps my inner ears tremendously with the air pressure fluctuations - maybe you'll want to do the same. Hint - gum also costs significantly more at airport kiosks than it would if you bought it in advance at the grocery store or Target or Costco.
5) If you have a cell phone, take it along. Even though I do not have a nationwide calling plan, it just makes me feel better to know I could call home to loved ones in any kind of emergency. BUT be prepared to turn it on/off at security if they ask you to do so, and make sure to turn it fully off when you get on the plane, as the electronics can interfere with the plane's own electronics.
If you have any more questions, please feel free to FReepmail me or respond to me on this thread.