I have been trying to find some well presented and explained Vector and Quaternion resources recently to brush up on my 3D skills, and have been having some trouble.
Most of the resources I have found tend skip over the high-level reason that performing a particular operation is useful, and dives straight into jargon and proofs that tends to loose my attention rather quickly.
I have found that better explained has really good explanations of various math topics, however doesn't have anything for Vectors or quaternions.
Does anyone know of any high level Vector and/or Quaternion tutorials?
Get 3D Math Primer for Graphics and Game Development. It's not a free online tutorial, but I seriously doubt you could find any online tutorial that covers 3D math in such detail while still being very accessible and beginner-friendly. It's got the best coverage of quaternions that I've come across, and it also introduces all the mathematical formulas with a geometric interpretation so that you know how they relate to computer graphics.
Other than that, here's a good basic Vector Math Tutorial. For Quaternions there's the Wikipedia article and some other resources you could find with google, but they all seem too brief or tied to a certain technology. Again, just buy that book (or alternatively this one which covers more topics but spends less time on the basics).