In this Software video tutorial you will learn how to combine documents into a single PDF in Adobe Acrobat 9. Go to the 'combine' menu and select 'merge files in to a single PDF'. Click on 'add files' and 'add folders'. Now create a new folder and click OK. Then drag and drop files in to the folder. You can then arrange them in the order you want. You can also delete any document that you don't want. You can also choose pages from a document. With all the documents selected, you can go ahead and select your file size at the right hand bottom of the page and that will compress these documents. Finally click 'combine files' and you are done.