You obviously haven't read about apply/eval. SICP is a great book. It's even available online! There's also the lectures.
SICP: http://mitpress.mit.edu/sicp/
The part about apply/eval: http://mitpress.mit.edu/sicp/full-text/book/book-Z-H-26.html...
The lectures: http://groups.csail.mit.edu/mac/classes/6.001/abelson-sussma... (apply/eval is discussed in Lecture 7, the meta-circular evaluator. I'm not sure if you could understand it without watching the previous lectures, however they're all wonderful)
SICP: http://mitpress.mit.edu/sicp/ The part about apply/eval: http://mitpress.mit.edu/sicp/full-text/book/book-Z-H-26.html...
The lectures: http://groups.csail.mit.edu/mac/classes/6.001/abelson-sussma... (apply/eval is discussed in Lecture 7, the meta-circular evaluator. I'm not sure if you could understand it without watching the previous lectures, however they're all wonderful)