While this tutorial and the FAQs should answer many of your questions, you may want additional help. There are two additional resources available: the NCHS email query and the NHANES listserv.
The NCHS email query is the main vehicle for asking survey related questions and responses are likely in about 24-48 hours. The listserv was created to disseminate information regarding NHANES activities, products, and release dates. Listserv users may also choose to interact with each other about their NHANES related research and to form collaborative relationships.