I bought this book as I was looking for patterns that would fit my 5 year old son. He's about average height/weight for his age, so I went for this book rather than knitting from the "9 to 5" book that I already own (which has patterns starting from age 5/6). This book has patterns up to age 4-5, which I thought would be fine for him.
I have knitted the Boys Hoodie - and although I didn't enjoy the swathes of stocking stitch, I could see it was worth it for the lovely looking garment that was emerging. However, even though I was extra careful about getting the right gauge (and even re-started the garment after realising I was way out), this is HUGE! It fits my 9 year old daughter! My poor son, who was very excited about the new jumper, will have to wait 2-3 years before it fits :(.
The book is lovely, and the tips at the beginning are great for beginners, helping them to knit the items within the book. But, please be careful about the size you pick for your little one!