...
If you are interested in buying the ebook cited above, "Take “Take Control of Maintaining Your Mac, Second Edition", it's Edition”, it’s available for $10 here:
http://www.takecontrolbooks.com/maintaining-mac
Disclosure: Oliver performs contractual work for the publishers of this title. He welcomes your questions about Take Control's many other titles and services, of course
Keywords: Mac, size, usage, disk, hard drive.