Now in its fifth printing since 1986, The Little LISPer has become The Little Schemer. (There is also a sequel now, The Seasoned Schemer.)
This book, by Daniel P. Friedman and Matthias Felleisen is the most unique programming book I have read. The authors advise reading it in no less than three sittings, which at first seems like a silly statement to make. Who reads a programming book in less than three sittings anyway? Well, it turns out they had a point after all. It would be ridiculously easy to breeze through the text, taking it all in at once. But then you would miss out on the enjoyment, and miss the point. I found reading it one section at a time worked fairly well. You really need a breather after the grilling they give you - remember, the entire book is a series of questions.
This book is silly. At the end of the first section there is a box with the words This space reserved for JELLY STAINS! inside. And all the variable names have to do with food. Great fun! This book is definitely a winner, and it teaches recursion so well I wish I had picked it up years ago.