I just bought a set of rims and the stamp on the back of each wheel states their 17x7, but when I measure them they are 18.5" across and 8.75 deep. Am I measuring them wrong or have they been stamped incorrectly?

did they come with tires?

myspace.com/coastiecobb

You are measuring from "outside edge to outside edge" of the rim in diameter and width? If so, then yes the measurement will be off because you measured the "overall" width and diameter The rim "fits" a 17" tire. It is actually the dia. from the inside of the bead seat area and between the rim bead "lips".
No worries kid! Your good!

So now at 44 what the hell do I do?