I can't trust anyone who doesn't peel the plastic film off their devices.
MICROCONTROLLERS
Everything microcontrollers: projects, questions, new releases, etc.
dragontamer's Beginner Guides:
Beginner Series I: What is a Microcontroller?
Beginner Series II: The "Generic" Microcontroller
Beginner Sidenote: Microchip's Signal Chain Design Guide
Beginner Series III: Skills and Complexity Tiers
Beginner Series IV: Deep Dive into Microchip's AVR EA
Just remember, Johnson Noise (aka: Resistor noise) and Reverse-avalanche Shot noise (aka: Zener Diode reverse current) are both quantumly random events at fundamental physics levels. So you can get fundamental "true" RNGs using a cheap Zener diode.
Johnson Noise is very small though, so if you try to amplify Johnson noise, its probably going to be other noise in your system in practice (ex: P-N junction noise in your transistors/amplifiers). So I think the Zener Diode noise generators are the most elegant solution.