It is hard to discipline a child

I've been so busy lately because as you all know I am working and when I come home I still have to prepare for dinner while taking care of my two toddlers. My baby girl is now already One year and three months old and as usual she is so curious with her surrounding that she wanted to taste everything that interest her. It is at this stage that she is already active in exploring our place. She wanted to roam around the house touching everything that comes her way and put everything she can grasp inside her mouth. That is why I have to sweep the floor so often to make everything clean. My son is already 3 yrs and eight months old right now and his behavior is a major adjustment to me. I think it is so hard to discipline a child and there are major issues that you have to look into. In the past as children we were spank with leather belt by our parents as a form of punishment and I know how it hurts during that time. I even have a scar in my right leg that reminds me of the pain and at an early age I could not remember what I have done to have that punishment. I think there are other options to discipline a child other than that kind of punishment but sometimes it is so hard not to do the traditional way of doing it. I think speaking to him at eye level would do and in a firm way but the must important thing is to have an enormous amount of patience. It is hard for me because I really don't like hearing him cry because when he wanted something he would ask for it over and over again. I'm telling him to stop trying to hurt his sister but for him, it is just some kind of a game. I hope there would be some kind of training to mothers like me in the right way of disciplining a child because the how we train a child will surely affect the formation of their character and I know that it can affect him psychologically.