The Little Schemer may be slightly better, but on its own, it too is not about learning Racket.
Although they overlap on some topics, comparing little schemer to htdp is comparing apples to oranges.
Also, htdp is just racket in my opinion, it differs very little from the students languages, I did the whole thing using just plain racket and didn't have any problems that couldn't be solved in two minutes visiting docs.racket-lang.org (and they were rare), but sure, you won't get to know all of racket because that's not the point of the book.
I do think there is a need for more YouTube videos on the basics. I seriously think Racket is way better than any other for scripting and quick programs. It just needs some more libraries which comes with more developers.
THE ONE WEAKNESS OF RACKET = Everyone just solves the same problems over and over again because it is so fun and easy.
Most dense book ever
Took my 30 restarts to get through it. This is my way of doing programming books: Read till I get stuck or feel unconfident in what I learned. Restart at page 1 and I ALWAYS get through where I was stuck. Get stuck go back to page one, rinse and repeat.....
Seriously I am an old fart that read a book to learn Assembly for C64 when I was 11. I have never had something fundamentally change the way I do anything. I mostly write R and my R writing style is night and day different and I could use the Scheme parts of it.
Highly recommended.
Secondly, go through Realms fo Racket with a kid (I did with my 10-year-old daughter). Teaching is the best way to learn.http://www.realmofracket.com/
This book specifically is in need of significant editing.
As an alternative, see the incredibly good “How To Code” class from UBCx on EdX (don’t be put off by the title). It’s a direct implementation of the approach in this book.