If you could make a starter kit for a first-time Airstreamer...

[Len n Jeanne]

The above lists are really super! I can only add that a lot depends upon the kind of camping you do. If you plan to stay in RV parks with full hook-ups in the Middle West, that is different than spending a couple of weeks in the back-country in southern Utah.

If you get up to provincial parks in Ontario, Canada, a long extention cord comes in mighty handy, as the electrical hook-up may be a ways a way from your actual site.

For a more "primitive" camping experiences in the western states and BC we take: generator (Honda 2000), gas can for said generator, a 7-gallon plastic jerry can of water plus a lot of smaller water bottles, a funnel for pouring water from the jerry can into the freshwater tank, an axe or hatchet. Then we basically make sure we have a duplicate of any really essential system, such as flashlights/lanterns, extra beding for cold nights, perhaps a small backpacking stove, and tons of matches.

The other issue for more primitive camping is not only what to take, but how to conserve what you have, such as power and water.

Murphy's law can kick in on camping trips. In fact, I am pretty sure Murphy was an RVer.

[mandolindave]

#1 Mandolin
#2 Spare mandolin strings
#3 A big dog to chase off banjo players
#4 A spare big dog to chase off people who forgot spare mandolin strings

[Woosch]

Good lists. Might want to get a copy of "The Newbies Guide to Airsteaming".

[BeachHouse]

Get the Airstream Newby book
All the above lists are great but get yourselves a checklist for leaving and arriving. Follow it without fail each and every time!! Avoid damage and insult!

[MTsafari]

A martini shaker and plenty of vodka.

[webspinner]

I would also add:
2x6 boards in 2' and 4' lengths (we find these more versatile than the leveling blocks)
a binder to hold trailer related info: registration, instructions, reservations, etc.
duct tape and gaffer tape because you just never know