For your possible interest, Take Control Books is offering a 50% discount through April 14. The first link below is a book about Mac basics, and the second link is to an index of all their books.
Jim Hamm
Take Control e-Book on iOS 9
There is a new e-Book available that you might want to take a look at. It is a crash course on iOS 9. Visit takecontrolbooks.com (click here) and use your MUG discount to get this e-Book with a 30% discount.
While you are there, notice that there is also a new e-book out on upgrading to El Capitan.
You might want to bookmark that link for future reference.