New CRM User Should Be able to see ONLY his OWN CONTACTS or LEADS...??

New CRM User Should Be able to see ONLY his OWN CONTACTS or LEADS...??

Dear Team,

We want to add a new user, but want him to see his own leads / contacts / accounts; but he should not be able to see all contact or leads or accounts already in the CRM or created by us....

... But, as an administrator we should be able to access his data, and NOT vice-versa..

Kindly assist in the same as its a priority..

I had been trying to each your call centre but had been put on hold for a long time.

Please help me...!!