PSA: @stephaneducasse has collected many great Smalltalk books and made them freely available!
Blue Book (on implementing Smalltalk): stephane.ducasse.free.fr/FreeBooks/Blue…
Red Book (on the Smalltalk IDE): stephane.ducasse.free.fr/FreeBooks/TheI…
... and many more: stephane.ducasse.free.fr/FreeBooks/
