If you only have reader you cannot do this. You need Adobe Acrobat Professional as other posters have said. Depending on which version you use there is an option from the file drop down menu (v7) to combine/merge multiple pdf files. In v9 this option is available in the tool bar at the top. When you have selected your 5 files the software will automatically create a new file and ask you to save it. The default name for the new file is binder.pdf