DWChiver,
Nice that you got a book and a starter kit for the arduino. Your first project is however a bit too ambitious.
But let's see.
You can power most sensors (as long as they are standardized) with an arduino with 5 V (There is a version of the pro mini, that runs at 3.3 V). Make however sure that the Instensity of the current is enough, as the arduino Uno for example offers 40 mA on each pins. Conclusion: You need to calculate, the current coming to the arduino, the current left and used by the sensors, therefore it would be wise to get a multimeter too.