https://opendatakit.org/use/2_0_tools/introduction-to-odk-scan/ -- is an
introduction to ODK Scan's features and use cases. There are also
instructions that detail how to create a Scan compatible form and how to
use the app to digitize your data and integrate it into the rest of the ODK
2.0 tools.
Scan is currently in Alpha status. It is designed to work with the "rev
126" version of the rest of the 2.0 software, which contains tools in
Alpha and Beta status. To understand what we mean by the Alpha and
Beta designations, see
http://opendatakit.org/use/2_0_tools/#Release_Designations
http://www.google.com/url?q=http%3A%2F%2Fopendatakit.org%2Fuse%2F2_0_tools%2F%23Release_Designations&sa=D&sntz=1&usg=AFQjCNEkO2QLW2_BuSzcZxHaVc7W8-wk9Q
See this post for more information regarding the "rev 126" software:
https://groups.google.com/d/msg/opendatakit/mKapG3stx-M/DSA3QOp-WKAJ
The Scan release notes can be found here:
https://code.google.com/p/opendatakit/wiki/ScanReleaseNotes