I get a few people asking me what the best way is to learn electronics. For me nothing is better than actually doing electronics and seeing all the stuff happen right in front of you. Perhaps the most useful tool I own is a tiny USB oscilloscope I bought years ago from Measurement Computing.
An oscilloscope can do something that a meter really can’t – it can let you see inside the circuits you are building and watch the behaviour in real-time.
Oscilloscope technology moved to digital a while ago, which resulted in a glut of the older analog style scopes for sale on Ebay. Although not as trendy as their digital cousins, analog scopes are still very capable, and they have one advantage – real knobs that do stuff – no shifting through menus of functions and up/down buttons – lots of knobs and they all work quickly.
I recently bought a Tektronix 4 channel 350Mhz scope for around $300 – this one has partial digital capability (setting storage and recall, voltage and frequency/phase “calipers” and a computer interface at the back).
The computer interface had to be installed, so I opened it up – just take a look at the 80′s microelectronics – nowadays all that stuff would be on one or two chips.