Possible Duplicate:
Where can I find C coding exercises to practice?
I am learning c programming language and i need some exercises resources to practice from.
Possible Duplicate:
Where can I find C coding exercises to practice?
I am learning c programming language and i need some exercises resources to practice from.
Find something that interests you and try implement that. Failing that if you like mathematically inclined challenges try http://projecteuler.net/ .
As opposed to the more mathematically-oriented exercises of Project Euler, the Kernighan and Richie (K&R) C book (The C Programming Language) contains exercises that walk through the various language features and how to use them correctly. I highly recommend it.
To clarify: if you do the Euler problems in C, you'll learn a lot about math and a little about C. If you do the K&R chapter exercises, you'll learn C.
How about the C Puzzle Book? http://www.amazon.com/Puzzle-Book-Alan-R-Feuer/dp/0201604612/ref=sr_1_1?ie=UTF8&s=books&qid=1285004754&sr=8-1
There are lots of problem sites. Here's a few: