I would like to know how to instantiate megawizard programs in my code. please help!

--- Quote Start ---

I want to learn everything about megawizard, instantiating the inbuilt code and about libraries related to that. please give me sufficient guidance how to do it.

--- Quote End ---

You can look into the transceiver design examples at Altera wiki (http://www.alterawiki.com/wiki/category:transceivers). These designs should have the info related to megawizard generated instances, how to instantiate these into top level and together with simulation examples.