We briefly touched on Touch ID in Chapter 1, iOS Security Overview, but more implementation details around timeouts and other key-related interactions are better describe Apple's own iOS Security – White Paper (as they go to great lengths to make things as understandable as possible). At the time of writing, the most recent PDF was from October 2014 and it can be found at https://www.apple.com/privacy/docs/iOS_Security_Guide_Oct_2014.pdf.
As Touch ID should still just be considered an added convenience, sufficiently complex passcodes are, as always, recommended in all things that are security-related.
Tip
If your customers or users are like ours, they will forget their devices' passcodes after getting used to using Touch ID. Therefore, make sure that you do not leave your customers in a situation without MDM management (or backups, if your organization encourages it), especially if the ActiveSync-based "failed password attempt" limit is configured. Once...
