Learn C Programming
This introduction to C programming originally written in 1993 by Christopher Sawtell is provided here as reference material. It's not going to make a C programmer out of you overnight, and you're not going to be able to program something like DOOM after reading it. Making a great game or doing any type of complex programming takes years of effort, but this - at least, is a good starting point. It is suggested that you print out each lesson and study it throughly.
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Lesson Number One
Lesson Number Two
Lesson Number Three
Lesson Number Four
Lesson Number Five
Lesson Number Six
Lesson Number Seven
Lesson Number Eight