hello Sewwandi:
Cherry's answer is very good too.
but here i want to give my answers simply.
yes=shi de(是的) / dui (对)
no=bu shi(不是的) / bu (不)
Sample:
are you hungry? (你饿了吗=ni e le ma?)
Yes, i am hungry. (是的, 我饿了= shi de, wo e le)
No, i am not hungry. (不, 我不饿=bu, wo bu e)
do you want to go shopping? (你想去逛街吗=ni xiang qu guang jie ma)
yes, i do. (是的, 我想去=shi de, wo xiang qu)
no, i don't want to. (不, 我不想去=bu, wo bu xiang qu)