You can buy an annual National Park pass here if you can manage to convince the person manning the register that they sell them and you can pick up free pre-printed information about trails in Olympic National Park and the National Forest. They do not sell the one-week entry passes for the park here, only the annual pass. It's in a convenient location just off 101, near the Hoodsport USPS, in a small plaza with plenty of parking. Staff is courteous but not as knowledgeable as what you'll find inside the national park. They also offer a small selection of used books for sale with proceeds going to the Hoodsport library.
This is a very nice visitor center. It clean, warm and equipped with a friendly staff personal. It had a good selection of travel brochures.