I don't want to be seen as advertising products and services, but as I wrote the book not to buy a villa in the Bahamas, but to help fellow techs diagnosing faults, I am hoping that I won't get flamed for posting this message?
I have written a book on oscilloscope diagnostics which deals with the basics, right through to advanced techniques such as current waveform analysis (using a low current probe) which you may find useful.
If you would like a copy (just £32.75 including P&P) please send me an email.