A full 98.8% of all material on P2P (peer-to-peer) networks is comprised of copyrighted material. A full 2/3 of that material is illegal to share. 91.5% of files on filesharing sites are copyrighted. So while you may, in fact, be referring to that miniscule percentage of files that are not copyrighted or illegal, the odds are against you on this subject.
Since piracy / bootlegging is something that we at Android Forums expressly prohibit, there is no reason to even discuss the subject in a "how-to, where-to" manner as if everyone reading will be using the information for that small 1.2% of legal and non-copyrighted files. So there is no point in proceeding with any conversation that deals with torrenting, because the word is essentially synonymous with piracy.