Pretty fair evaluation of what to expect and what can be encountered.

This was a good book, but much of it contained information I already knew as a road runner, a backpacker/hiker/mountain biker, and a former outdoor industry employee. Still, I learned some new things (like the history of trail running) and tried to better understand some running metrics that seem to confound me (like VO2 max and lactate threshold). If you’re brand-new to trails in any form, it’s definitely worth a read - even more so if you don’t have a road running background. If you have a strong background in the outdoors and/or running, you probably don't need it - but if you're curious, check it out of the library or buy a used copy. You won't need it for reference moving forward as you'll already have the knowledge you need.