THis might seem like an odd choice for my review list, but it's one well worth putting up here, I think.
First of all, this book has continually been a godsend. Not because you read it and then know everything-you-need-to-know about parenting a toddler (you don't) but because it's one of those books you can pull off the shelves during those moments when everything is going wrong (ie: 2 year old screaming his / her head off, bashing it on the floor while simultaneously throwing his / her dinner, biting anything within range, and throwing yoghurt at the wall. In a supermarket. In front of your parents.) and find, if nothing else, the reassurance that you're not doing anything wrong.
Unlike a lot of the other baby and toddler 'how-to' books on the market, Barker is in no way didactic or judgemental, but simply takes a down-to-earth approach to pretty much everything. Which, when it's the middle of the night and you're second guessing yourself, is a very handy resource to have on tap.