Vellum I is great for beginner and intermediate users alike. What makes it stand out is over 19 exercises that explore a variety of constraint types. Some exercises are guided in the videos, and other exercises don't have an answer key. This allows you to learn better through practice, and it gives you an opportunity to try things out on your own without the challenges being too overwhelming.
In addition to the exercises and over 6 hours of video, you'll also find resources that provide extended definitions of vellum nodes and diagrams that help you decide on which constraint type fits your situation. These resources are part of the exercise file, and it's helpful to refer back to them when problem-solving situations on your own.
Out of all the solvers in Houdini, vellum is one of the most versatile tools in a FX artist's toolkit. Some of these challenges include classic situations like cloth, hair, and tearing effects. However, vellum also goes beyond that. You can use vellum for denting, plant wind, mud, snow, growing fx, particle simulations, skin, muscles, and much more. That makes Vellum a necessary addition to any FX artist's toolkit, and Vellum I will help you reach a solid level of proficiency much more quickly.