Three Options for Purchasing the Outlook Book
Best Price: From Michael Linenberger's web store

For the very best price, buy directly from Michael Linenberger's web store.

(if you have a team or department, bulk purchases of the book are also available; call 925-735-3920 for details).

Amazon
Amazon.com has the next best price. Use this link to buy it there.
At your local Borders or Barnes & Noble physical stores

You'll pay more, but at least you get to hold the book in your hands and look it over.

Search Inventory first: the title is often sold out at these stores, so you may want to check inventory online before your visit. Here are links to do that; just search on the book title (be sure to locate the newest edition) and then use the zip code lookups on the book page to find local availability.

Borders: borders.com

Barnes & Noble: bn.com