There are a few key elements to successfully promoting a self-published book:
-It is a good standard to have a professional book binder as a business partner, or as a business associate. Self-promoted books, should ultimately have the same look/feel as marketed books, because people will see them as book, (and not stacks of paper).
-Be prepared to invest hundreds, and do not expect to see an instant cash return. You will need to type, edit, revise, print, (which all adds up in expenses).
-Book signings are a must. Self-promotion does require a bit of face-to-face contact with people, especially with a paperback book. Unlike an e-book, a paperback is almost entirely offline. Sales can happen online, but there is nothing instant about a paperback.
-Expect to wait a year or two to see any profits, because during that time is when a writer will establish their audience. Also, most writers will see a increase in their audience after only a few months, (because that is when most people will finish reading, evaluate, and then share with their friends).
-Online promotion can be tricky if a writer isn't particularly good at web design. There are a number of easy-to-design website hosts that offer free services, such as, Weebly. Also, SEO (search engine optimization), is a good way to get a site on the search engines, and is an essential tool for building a broader audience.
Best of luck to your friend,