Make sure the bindings fit you!
Bindings have what is called a "DIN" number. For interest DIN stands for something in German I beleive...but is just a standard...hence a DIN of 6 on one binding is the same as a DIN of 6 on another.
You need to know what your DIN number is...then get bindings to match. This may seem daunting, but in actuallity is easy as all bindings have a range...say 4 to 10 is common. As an adult, unless you are really big, or really small, you will fall in that range.
Hence once you have found bindings in your range, the next thing you need to check is that the binding fit your skis...or more precisely that the ski brakes are wide enough to fit your skis. Again should be easy....just look at how wide your skis are in the middle....then make sure the binding brakes are wide enough to fit.
Just a tip thou....make sure you get a shop to mount the bindings and set them up for you...if you buy them online you will pay a fee to mount them...typically $30 to $50, so factor that in to your cost...typically by the time you pay for shipping, and mounting your online purchase will save you very little...if anything.