I also think Racket is a good introduction to Lisp. The documentation is great. Take a look at the vector documentation as an example http://docs.racket-lang.org/reference/vectors.html?q=vector&.... If you are not familiar with the language, there are plenty of examples to help you get going.
I recently started working through The Practice Of Programming and I wanted to compliment it with a functional language. I thought it would make the on ramp to functional languages a little smoother by first coding something in a language I'm familiar with and then port it over (producing more idiomatic scheme is the next iteration). I chose scheme as the compliment and PLT/Racket as the environment. So far, it has been working well.
I recently started working through The Practice Of Programming and I wanted to compliment it with a functional language. I thought it would make the on ramp to functional languages a little smoother by first coding something in a language I'm familiar with and then port it over (producing more idiomatic scheme is the next iteration). I chose scheme as the compliment and PLT/Racket as the environment. So far, it has been working well.