Teach Yourself Visually Knitting Design

Teach Yourself Visually Knitting Design: Working from a Master Pattern to Fashion Your Own Knits is a book that every knitter should have in their personal library. While this book is more about original design than adaptation, there are stitch numbers that can help you convert a pattern for an adult to a baby. It is a handy resource to quickly calculate from your gauge swatch how many stitches you should cast on for that hat.

I own this book, and you should, too!