I want to write some programs and even games using graphics of C.Please Help me to write these.

The C language doesn't know squat about graphics. You need to learn about the third party APIs (such as Qt, Win32, Allegro and SDL), choose which one you want to use based on the needs of your programs, and then learn how to use it.

It goes without saying that a strong foundation in the basics of C programming is critical if you don't want to stall out trying to learn an API but while still struggling with language issues.