Here are some resources that I’ve found for Audio Engineering.
Excellent source of audio test and training material. Definitely useful to help learn and train your ears!
- EQ Cheat Sheet
Sounds typically heard in various frequency ranges plus instruments and their typical highlight spots.
- EQ Your Ears
Another website that lets you focus on training your ears to identify 1/3 octave frequency centers.
- Multitrack Stems for Mixing Practice
Nifty site with some public domain multi-track recordings that you can use as a source for practicing your mixing technique and learning how to use a sound system. Save them to a hard disk and use them in your multi-track DAW as a feed into your mixer.