[racket] Questions from a new user

Steve, welcome to Racket.

Regarding your Scheme questions... Unless you have an unusual reason 
that you need to use some Scheme dialect, rather than Racket[*]... then 
I strongly suspect that you want to just learn Racket for now, without 
everyone getting confused, talking about the various dialects of Scheme. 
  (The situation is different than, say, standards of FORTRAN.)

[*] Hypothetical reason why someone would want to learn 'Scheme' rather 
than Racket: they want to code for an old microcontroller for which 
there is only an R3RS subset compiler.  If this is your situation, then 
let us know; otherwise, talking about 'Scheme' would be doing you a 
disservice.

Neil V.