When I took the ASTB there were a few basic circuit questions. Resistors and capacitors and such. I don't remembe r much in the ways of actual calculations, the majority would be "which one is greater/lesser". I'd count on needing to know the formulas for sums of capacitors or resistors in series and in parallel, as well as the force changes for different numbers of pulleys in a system. If you can find one, grab a formula sheet for AP physics (I think it was roughly 4 sides of 8.5x11 total) and throw out anything past basic mechanics and circuits. I hadn't taken physics in 3 years, and even then, the only class I took was high school physics, and I had no problems with it.
The verbal, no matter how much they tell you is straightforward, is completely and utterly misleading. No real way to study for it, just pay attention to detail and don't use "common knowledge" to make any decisions. The math is straightforward, basic algebra and geometry. Nothing really complicated.
The non-OAR parts however, I'd suggest grabbing the ARCO book if you can. I didn't get it myself, but I've been working at an aircraft company with a private airfield for 7 years, and I still spent the better part of a month on google looking stuff up. Also don't forget to look up nautical stuff, especially buoys, lights, and right of way. If you're going for the high score (and you should be) look up what the color of a pipe aboard a ship means.
Some links you might find helpful:
http://www.alpharubicon.com/bovstuff/commonnavigationlights.htm
http://www.erau.edu/er/newsmedia/articles/cont12.html
http://www.fish4fun.com/buoys.htm
http://www.google.com :icon_wink
