A valid passport is a necessary requirement for any type of visa. However, the required time remaining until the passport's expiration varies. For instance, applicants for a work permit need a passport with a minimum validity of 120 days while for students this is raised to a one year. Biometric passport holders of certain countries are exempt from the visa requirement for short visits. The Spanish Ministry of Foreign Affairs offers a complete list of these countries on its website.
Applicants for a tourist, work or student visa are required to complete four application forms, as well as provide an equal number of recent passport-size photographs. Prospective workers need a copy of the "resolución de permiso de trabajo" (work permit offer) issued to the employer by the Ministry of Labor and Immigration. Students need a receipt confirming they have enrolled at a public or private study center recognized by the Spanish government.
For a work visa or a student visa for a course lasting more than six months, a health certificate, along with one photocopy, is essential. The certificate must state that the applicant does not suffer from infectious diseases listed by the World Health Organization, mental disorders or drug addiction. The document must be translated into Spanish by an official source. In the U.S., you can turn to authorized translation agencies, such as Spanish Translation U.S. and Translation Services USA. All documents must be presented to a Spanish consulate.
Apart from a health certificate, the aforementioned categories of applicants need to provide a police criminal record certificate, an original and a photocopy, which -- as the Ministry's website suggests -- must "state that the applicant does not have a criminal record." The certificate must be from the country -- or countries -- where the applicant resided for the past five years. As with health certificates, applicants must provide an official translation for non-Spanish penal records.