<<Disclaimer: Verify this information before applying it to your situation.>>
 
The alleged educational use of copyrighted material is not the same as
distributing to 1000 people on the internet.
The wishfull dreaming of rationalizing piracy of copyrighted material because
it may result in the purchase of books or products described is just that,
"dreaming" and not described in any legal determination of "fair use" of
copyright material.
Of course, all of us want to help each other, let's keep the relevant issues
in perspective. Pirating copyrighted material has nothing to do with helping
each other.
All you have to do is get permission from the author.  If you are afraid the
author won't grant it, then it is probably a copyright violation.