Re: #6: As you have already noted, be mindful of liquids, make sure to follow the 3-1-1 rule (see TSA site), place in correct size bag, and remove for x-ray. YMMV, but some have reported that 3-1-1 is not overly well enforced, but for a first time flyer, best bet is to follow the rules to the letter (IMHO).

Otherwise, make sure not to carry any weapons (guns, knives, etc) or anything that might be considered a weapon (trailer hitch, baseball bat, razor, etc). For long flights, make sure to bring something to keep yourself (and junior) busy. Some airlines still consider the window to be sufficient in-flight-entertainment.

If you plan on checking a bag, you can basically take anything without much restriction. But just don’t pack anything valuable in a checked bag (i.e. laptop, camera, etc). Also note, some airlines may charge for checked bags, (rates vary based on domestic/international, amount of bags, and weight). Check your air carrier’s website for the baggage policy.