There is no real definitive guide , many sites will cover the basics
but from there on electronics branches many ways, am not saying
one cannot learn it all , but it will take time.
Building your own test gear is always a good place to begin when starting out. Power supplies , Signal / Waveform sources , freaquency counter..
I was going to say logic probe as well but given the rise of microcontrollers
a parallel port interface for data logging would be more usefull.
Etching your own boards is an art in in itself for the hobbyist and fraught with dangers never mentioned in the text books..I still wince at the beating my mother gave me for "borrowing" her big pyrex glass dish.