How do I use vos, vosotros, os, and vuestros in spanish?

You will only use them is Spain, and almost never in any other Spanish speaking country (except in the Bible, where they are used often). You would use them when speaking to a group of friends, subordinates, or children. You would use each of them in the same grammatical ways that you would use "nos, nosotros, nos, and nuestros", except obviosuly when referring to others and not when referring to a group that includes yourself. "Os" is the indirect object pronoun, and "vos" is the direct object pronoun. Vosotros would be used as the subject of a sentence, and vuestro is the possessive pronoun.