Good things with Origami Step-By-Step: 1) it's very inexpensive, and 2) it has a good number of fantastic models the likes of which would be very difficult to find in another anthology. Patricia Crawford's designs are innovative and original not only in form but also in content. A few of the more original models include a birdbath (with birds), a squirrel on a log, a mermaid swimming along seaweed, and Christ praying on the Mount of Olives(!). Her other models are perhaps slightly more characteristic of origami -- cat, kangaroo, unicorn, scorpion, three-masted sailing ship -- but are also very well-conceived.
A few caveats of Origami Step-By-Step: 1) the overutilization of foil-backed paper. The intro states that the tensile strength of foil is actually a necessity for many of the models. I have not tried folding all of these models yet, but I suspect you may be able to get similar results using wet-folding techniques. Still, I would have liked to have seen less models that depended on the malleability of the paper for its effects. Also 2) the instructions are anything but "step-by-step." In most of these models, many steps are combined into single steps, making a first-time fold very difficult if you don't already understand the mechanics of the folding. These models rely heavily on pre-creasing, and you can expect to see the first step of a given model to be a square with numerous dotted lines criss-crossing everywhere indicating the creases, but not the folds that lead to said creases. Needless to say, this book is not one for beginners, and even intermediate to advanced folders may be stymied by the lack of instruction.
Still, this book has some models you won't find anywhere else, so it's definitely worth a look. Just don't expect to go through it in a day.