[AI2V]

Here's a mandatory course for oscilloscope instruction: http://www.njarc.org/scopes4dopes/

My scope is used daily in troubleshooting; it allows me to "see" what kind of signal is riding on my screen supply, how much ripple is in the supplies, signal levels, and very importantly, audio distortion.

You will be needing a pair of probes, preferably the kind that is switchable from 1:1 to 10:1 divider. The purpose of the 10:1 divider is not necessarily for the dividing function but more as very high impedance that won't load down the circuit under test. They are quite inexpensive on Ebay.