Alan Kay's recommends reading these books
While watching Alan Kay's talk at OOPSLA 1997 I took note of these books, which were recommended by him.
The Active Creation (I'm not sure this is the correct title)
The Art of the MetaObject Protocol, ISBN 0262610744 (Interesting enough this book was written by Gregor Kiczales )
Smalltalk-80: The Language and its Implementation, ISBN 0201113716