There is no paper book for Squeak yet. When I wanted to teach a friend
Smalltalk, and he insisted on a paper book, I got him the grey
asparagus book (P.H.Winston) and wrote an item by item description of
what he should do different for Squeak. I still have that list of
differences, if you decide to use the book I can send it to you. Most
of what makes Squeak so good is not in that book, but if you don't
know Smalltalk at all and insist on a book, it should get you started.

If you don't *insist* on a paper book, I think reading the sources is
the best way to learn.

-- 
Stan