I highly recommend checking out the Make: Electronics series. You can also buy kits for each book on Amazon if you don't feel like going out and finding all the parts yourself at RadioShack.
The 8-Bit Computer video series by Ben Eater (reshared on HN recently, https://eater.net/8bit/) was the first thing I saw which ignited a passion for understanding the hardware underpinnings of computing.
ElectroBoom, GreatScott, EEVBlog, Julian Ilett, and Adafruit YouTube channels are really great, too.