Questionnaire for Hiring Contractors/Employees

I'm going to have to start hiring some contractors, and possibly some employees, soon. I notice that a lot of other business Web site will have a questionnaire for new applicants. (i.e., "Are you a US Citizen?", "Have you ever served in the military?", etc.). I was wondering if I legally need to give this questionnaire to prospective contractors and, even if I don't, what the name of this questionnaire is, so I can find an example on the Internet?



I know it's legally impermissible to ask a prospective employee/contractor their race, religion, US Citizenship status, etc., but was wondering how to implement this questionnaire and where to find it?



Thanks.