I don't think that's what he means... while Satcomer's suggestion will make the document a "read-only" document in terms of UNIX permissions, there are Adobe-specific ways of making a document non-editable, non-selectable, and non-printable (which UNIX-style permissions cannot accomplish, especially if the document is transferred to someone else's computer -- they can override those security settings if on a Mac or Linux/UNIX computer, and they won't even work at all on a Windows computer).
I believe you'll need Adobe Acrobat Pro in order to do this. If you have that, select "Advanced > Security..." and create a new policy (with a password) that restricts printing and text selection... then apply it to the document you'd like.