I work for a large corporation's research department, and we build our prototypes using the.Net platform (which implies the product team always reproduces our work if the prototype is 'useful.')
For our projects, we also hire interns. Some interns are mostly involved in research and consequently code less. In any case, interns must be able to code in C# or, if possible, F#. The majority of them have never worked with C# before. They are usually senior undergrads or graduates who are familiar with Java and C++. However, they are unlikely to have obtained any formal programming training.
The difficult aspect is teaching them C#/.Net quickly enough for them to focus on their research difficulties during their 3- or 6-month internship. They also need to know some excellent C# practices, as the codebase they create during their internship will not be reusable afterward.
My approach to learning C# differs from that of others (I learned F# first, then read CLR via C# and Effective Java from beginning to end.) As a result, I'd like to seek advice from experienced C# users in order to recommend a short-term (say, two or three days) C# tutorial.