Programming for the consultant

Start with the acceptance tests to understand the features
Checkout the build file. Run the build to check the health of it
Sketch class diagrams (or reverse engineer from code)
Look at the main domain objects and what they do
Take a vertical slice. Select a main feature and see how it works from the front to back end.
Look at the source code repository, specifically at files that have changed the most. Checkout the log messages as well