If you are reading SICP or want to, Racket is also a good choice here. I bounced between SICP and The Little Schemer with Racket. I didn't use the SICP language until later on but I found that Rackets documentation was so good that it was pretty easy to fill in any blanks.

All in all, that experience was useful to me to both learn Scheme, learn core concepts, such as recursion, higher order functions, closures and so on whilst also paving a familiarity that has aided in quickly picking up CL, Clojure and also, in my opinion, Haskell.

I would recommend Racket whole heartedly.