I don't believe enough praise can be given to "The Little Schemer" (and the series). This book is wonderful at teaching recursion and is extremely entertaining. I've run by only a few books that can teach a programming skill like this without the need of a computer. Grab a pen/pencil, some paper and this series of books. Then take some time to just do it. It's more fun than sudoku, seriously. Again, you don't need to execute anything in a REPL. Your brain, that book and piece of paper is your loop.<p>(this space reserved for jelly stains)