Oscilloscope question

I'm rapidly approaching the point where I will need to learn how to use an oscilloscope as part of my quest to learn more about debugging the old DEC hardware. What kind of advice can folks offer to me about a decent scope and some info on how to use one? I think I used one 30 years ago in school, but it's been so long that I remember little-to-nothing about it. One of my first exercises might be to attempt a head alignment on an RK05 drive using an alignment pack. I have all the documentation for the drive maintenance, etc. What kind of scope would I need and how much does one cost? Are there any good web sites that would give some basic info on "scopes for dummies" or "scopes for beginners"? Thanks in advance for your advice. This is a never-ending learning experience. Ashley