You ought to see what's available in your classroom before you start stocking up. Once
you are hired, develop a mental plan of what you'd like to teach, then get into your new
room and see what's there. Obviously, if there's no kiln or place to store clay,
ceramics is out for a while.
The one thing I've spent a _lot_ of money on is slides. At the NAEA conference, the
Universal Color Slide Co. has a booth where they sell slides for $2 each, as opposed to
$2.50 from their catalog. If you know you're going, you can e-mail them a few weeks
ahead of time and tell them what slides you'd like to purchase; they will put together a
set for you.
I much prefer slides to videos as the image quality is superior and much larger, and
their use is much more flexible: you can show a single image or a whole series, and
spend time discussing them. Of course, a slide projector and screen are necessary!
Make sure you or the AV dept. provides you with a spare bulb to keep on hand.
Also, a friend who had purchased dozens of slides in Italy and Greece donated them to my
art room, and I gave her a receipt for tax credit. They've been wonderful for filling
in gaps in my collection. Put the word out to people you know who travel and see if
they'd be willing to do the same.
Hope this helps. Best wishes to you in your search for a job.