What sort of current should I be expecting to see when I turn the ignition switch on to the starter motor solenoid? I was expecting a small amount of current but another post on here has made me think otherwise.

The solenoid itself will take of the order of 5-10 Amps for a pre-engaged starter motor. A solenoid for an inertia type starter will be a bit less as it only has to close a pair of contacts. The starter itself will be drawing a lot of current; anything from 100-300Amps or more depending on engine size, compression ratio and temperature.