Apart from books that you can buy and refer (Apress Books for beginners/dummies as they call :) are good...)
For Online:
Start from basic programs... have a look here...
MSDN: Beginning website development using C#[
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There are lots of sites with beginner tutorials too:
http://www.programminglearn.com/370/net-tutorial-for-beginners[
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You need to know the environment setup requirements and then the working.
For a website development you must know about Page Life Cycle, how page renders, events work and navigation happen.