Originally created to provide an easier way to produce web content, Markdown is now an indispensable tool for developers and bloggers.
This intro text surveys Markdown and offers a reference and tutorial for both those who are new to the technology and those who want to improve their Markdown skills.
The core subject is actually quite small, so the authors have wisely focused on the bigger picture -- how do you use Markdown on various platforms and tools.
The book consists of text (130 pages) and screen casts (with over an hour and a half of video and an hour of audio interviews). Yes, the download is enormous -- 850 MB.
The book is well-organized and clearly written. The videos were pertinent and helpful -- they felt as if I had taken home my own little personal tech conference.
Markdown is not, in and of itself, a big topic. You can easily search for and find cheat sheets. If you're that kind of person, this isn't the book for you. What this field guide offers is a really pleasant introduction from experienced experts, who give you a warm and knowledgeable overview of the topic with a lot of depth. I don't think anyone will regret the purchase price of 10 bucks.
The book is available in both OS X and PDF formats from the author website. I reviewed only the iBooks version.