For SIJ University, we have collected more than 100 videos covering SI/PI/EMI basics for PCB design engineers. Rohde & Schwarz has provided some great introductory videos of test and measurement basics and Eric Bogatin's books provide great instructional videos detailing basic theory and practical tips for PCB designers.
Rohde & Schwarz fundamentals of Signal Integrity and test/measurement basics videos
Bogatin’s "Practical Guide to Transmission Line Design and Characterization for Signal Integrity Applications" book companion videos
Bogatin's "Practical Guide to Prototype Breadboard and PCB Design" book companion videos