Combining pdf documents on an Apple computer is easy. Leopard, Snow Leopard, Lion and Mountain Lion (the latest versions of Macintosh OSX) all have the ability to merge two different pdf documents together and even move pdf pages within a pdf file. There are lots of websites offering to sell software to do it, but you don’t need a third party program to do it – it’s built right in to OS X for free. Things have changed to make it a little easier with Mountain Lion so I’ve made a new post on merging two pdfs in Mountain Lion here, but for OSX prior to Mountain Lion, just follow the instructions below!
To join two or more pdf files together using Preview (the standard pdf viewer in OS X) simply open the pdf file in preview, open the thumbnail view (Shift-⌘-D), and then drag a second pdf ON TOP OF an existing page thumbnail. (It must be on top of the thumbnail, see the pictures below). The two documents will merge into one. Then save the new combined file. Read on for step-by-step instructions.