Practice problems solving in codechef.

I am new at codechef. How to practice problems in a codechef. Other online judge has catagory wise problems but i can not found catagory wise problem in codechef. Please help me how to practice problem in codechef. you can go to this link to practice category wise on Codechef
and to practice on different online judge go to A2oj site as it is specially for category wise practice questions follow this link of A2oj it has all the questions of different online judges category wise