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.
I think first time setup is a huge key for programming languages. For example Go has the benefit of an amazing out of the box standard library, unlike D and Ruby where you would install via a package manager the right tools to get a web project going, you could do it all from vanilla Go code.
Of course in both Ruby and D you could do it from vanilla code, but it's not as seamless and tried and tested I suppose?