Starter 101:
The starter mounted solenoid is connected to the positive side of the battery (on a '97 through a second fender mounted solenoid located near the battery).
The starter motor housing is connected directly to the negative side of the battery to insure a good ground.
There is a smaller gauge wire connected to the starter solenoid's "S" terminal. Some are bolted on, some are connected to a spade terminal.
When you turn the key to START, the ignition switch, located on the lower steering column, energizes the fender mounted solenoid (if so equipped) which in turn connects the battery's positive lead to the positive cable going to the starter mounted solenoid. Also, power is sent to the "S" terminal on the starter mounted solenoid, which energizes the starter motor and makes it spin, as well as pushing the starter gear into the flywheel's ring gear, which begins cranking the engine.
There is typically also a starter relay which "relays" the power from the ignition switch to the "S" wire.
What's not working?