I haven't counted, but I would bet that 8 out of 10 questions on this forum begin with some variation of "I'm totally new to electronics and programming ...". Being quite new to this world myself, I have been looking around for sources of knowledge and I thought I'd share two books that I have found to be very useful, even if they don't deal with the Arduino specifically.
The first one is Making Things Move, DIY Mechanisms for Inverntors, Hobbyists and Artists by Dustyn Roberts. It's a great book that is very hands on and easy to grasp, while still providing you with enough depth to understand the underlying principles. It provided me with mental tools and courage to go on and try my own ideas. A great and easy read!
The second one is Practical Electronics For Inventors (2nd edition), by Paul Scherz. Among other things, this book demystified all those capacitors that "inexplicably" show up in more or less every circuit you will find. I bought it as a backup option when ordering the classic The Art Of Electronics, by Horowitz and Hill. This is indeed a thorough book, but I found Practical Electronics For Inventors to be much more useful for me. Having both doesn't hurt though.
What do you read?