If you can’t find the info you need here, ask me anything: bgrugle [at] gmail [dot] com.
The Animated Guide to Compression
A visual guide to what compression is and does.
What Frequencies Sound Like Chart
A PDF that describes what frequencies sound like in actually helpful, subjective terms.
The Pro Tools Shortcut Bible
Why don’t they publish these??
EQ Explained
An easy to understand explanation of what EQ is and does without being loaded down with numbers and rules.
Loudness vs. Volume
There’s no perfect guide to understanding the difference, but this is close.