The patterns in this book are marvellous and the photographs charming; really it's a book that's worth owning for the pictures alone. As far as actually knitting the cats goes, the patterns are fairly clear, though the explanations of techniques in the back could have benefitted from some illustrations, and they produce much better toys/models than most other books I've seen, but be advised, if you don't know how to wrap and turn or pick up stitches, you won't be able to knit the cats. Fortunately there are a lot of good instructional videos on YouTube (knitpicks videos are particularly helpful, I find), so this rusty knitter was able to brush up her skills and have fun.
In terms of equipment, the patterns call for needles of 2.75mm, both ordinary and double-pointed, and use 4-ply wool - though of course, you can still follow the patterns using different materials if you want to. You're also advised to use pipe cleaners to shape the legs and tail, unless it's a gift for a small child.
If you're just starting out you should probably begin with something easier, but if you're experienced or ready to hone your techniques, this book is lovely.
Thought I'd come back and add to this review having had some more practice with the book. The more I use it, the better I like it. Having had some practice with the basic techniques of wrap and turn and picking up stitches (though there are some patterns where you only need to do the former), I'm finding the patterns are quite straightforward. Having said it's not for beginners in my original title, I now think that if a beginner can teach themselves a few basics, it's actually a very good book to start with: the patterns are very well laid out and the whole book is easy on the eyes, the cats are quick to knit and rewarding. I've used it as a jumping-board, and now my knitting's a lot more advanced.
The making up can be a bit of a fiddle and if you don't do it very carefully the cats can come out wry-necked or twisty-legged, and the 'standing up' cats tend to get a bit melty-legged if you don't stuff and pipe-cleaner them very thoroughly, so I've tended to stick to the sitting and lying-down cats. There's one particularly good pattern near the end for a lying-down but not curled up tabby (pp 130-133), and if I have a complaint it's that, while the authors offer a lot of variations on the standing-up, sitting-up and curled-up cats, they only offer the one pattern for the short-haired lying-down one, and as it's one of the most attractive patterns in the book, as well as one of the most stable once it's made up and sitting on your shelf or desk, that's a real pity. I'd really like it if they'd offered more variations on that theme.
But that said, it's an extremely good knitting book. I've made a lot of cats as gifts for people since getting it, and they've been received with universal excitement, and now my friends are all impressed with me!