Under $6 for a 775-page book delivered to your door!  The key to getting such a great price is that the screen prints and step-by-step instructions for using Excel 2010 or Excel 2016 are basically the same as for Excel 2007!  So buying this used book from Amazon (or elsewhere) can save you almost $30.

https://www.amazon.com/Master-VISUALLY-Excel-Elaine-Marmel/dp/0470181702/ref=sr_1_2?ie=UTF8&qid=1476383226&sr=8-2&keywords=excel+master+visually+marmel