I bought a Canon 450D (superb, by the way) a couple of months ago, having been a point-and-clicker until then (and playing around with friends' and family's cameras). I wanted a book that allowed me to make the jump in photo quality that I expected to get when upgrading to an SLR.
Having read all the reviews of these books (individually) I was very nearly put off by the criticisms of the writing style, but am very glad I ignored those and bought them anyway.
The books are great. Each page tells you something you can use to make your next photo better. It's not in jargon, doesn't go into techy detail, just tells you what settings you need to achieve the image you're after. I've learned a lot and have already seen the results in the pictures I'm now taking.
The big complaint about the author is the cheesy humour and yes, this is definitely there and is certainly irritating. It's an American book, written for an American audience. But it's only words and (as he says) he gets most of it out of his system in the first chapter.
I would heartily recommend that if, like me, you're relatively new to SLRs you should take a deep breath, ignore the 'yuks' and read these excellent books...