With all respect, I disagree with Dimcl on this one. You can say "a myriad" of books. A myriad is, according to Wikipedia, a hundred hundred, or 10,000, originally, and now has been broadened to mean "a large (or uncountable) number." To say "a myriad number of books" would be to say "a large number number of books."
Except a desire NOT to sound like either Milton or Thoreau.