I am new to C# , working on C# for windows mobile. I have done basic examples , however where should i get necessary documents (APIS , examples etc ) for C# so that i can explore more .
OK, assuming that you're already familiar with Visual Studio, Emulators Images, or have already worked with actual devices, you should already have obtained the latest Windows Mobile SDKs; these already include lots of samples and documentation for both managed and unmanaged APIs.
However, you oughta know, most hardware vendors provide their own very specific SDKs and developer's libraries (i.e., for managing barcode and RFID readers, third party bluetooth stacks, add-on hardware, etc.). I'm not talking about crappy smartphones here, but industrial devices such as Motorola's or Intermec's rugged mobile computers. You will have to sign up to gain access to their software libraries and knowledge bases, though.
Have fun.