I agree with Ion Filipski that U should practice to understand the OO Technology.
Its like to learn swimming U should enter water. But at the same time I would also say that U require a teacher who would guide u in case u get in the problems.
I have posted a problem which u could take as your case study and also help me in understanding the design of the same.
Traditional way, the problem has been, solved but OOT its pending.
Its thread678-135566