There’s an actual Dover Publications programming book that I really enjoy: "An Introduction to Functional Programming Through Lambda Calculus" [1]. So far it’s been enlightening, and even though it’s a 1989 reprint it doesn’t feel all that aged except for some of the semantics used (e.g. ALL_CAPS variable/function names).
The bibliography at the end is also a nice history lesson and very useful if you want to dig deeper into specific topics/paradigms the book touches on.
I'm working through this book right now and I'd like to give it a +1 as well. I worked through the untyped lambda calculus via Wikipedia a little while back but it was a struggle.
On the other hand this book's crystal clear exposition and exercises are like a breath of fresh air! Reading this first would have saved me a lot of time.
Yes, I have this book too and found it extremely useful and enlightening as well. I wrote a paper on functional programming concepts a few months ago and wrote a bit up front about the lambda calculus, and this book was how I brought myself up to speed. (Sadly, my undergrad CS did not even mention the lambda calculus, as far as I can remember)
The bibliography at the end is also a nice history lesson and very useful if you want to dig deeper into specific topics/paradigms the book touches on.
[1]: http://www.amazon.com/gp/product/0486478831