hi for all ,
can you tell me a way to learn C# completely in the least period ?
and what's the best book (free book) for this ?
and thank for you.

Try this:

http://www.dummies.com/store/product...Id-322467.html

Here's another good resource for ya:

http://msdn.microsoft.com/en-us/beginner/default.aspx

It walks you through a complete project from start to deploy in either VB or C#.

Seriously, BUY A BOOK. Do all the examples. Write your own code. Rinse and repeat multiple times with different books on different topics.

C# for Beginners
C# design patterns
C# advanced topics

Learning how to program is an on going process, there is no quick way to learn. You learn from experience, you learn from mistakes, you learn from others, you learn from reading and most importantly, you learn from writing.

You can learn from this site http://www.functionx.com/csharp/ .