There is a lot to tackle in a landscape if you think about it: all those different textures, colors and shapes.  Water, clouds, trees, houses, flowers... not to mention perspective and making an attractive composition.  For once, not much of a meal is made of what to buy, and I admired this brief but necessary advice, as beginners really do not need much.  Listing "credit card" made me laugh—until I realized that Mr Harrison was suggesting you use one for scraping out texture on rocks and cliffs!  Maybe this is a good way of introducing the book, for all sorts of tips and tricks are mentioned that most people would not think up on their own, but which make for good pictures.  Learn what basic palette you need, work through some staged pictures to gain confidence and discover how to get those all-important effects right for the most realism.  Discover how to use a brush handle to paint as well as the other end, work from photos or nature, and get the most out of a wide range of brushes and more.  I reckon there is something for everybody in this big book even if they are not beginners.

If you cannot find materials for watercolor painting locally try SearchPress.com for a list of suppliers.