Jakim,
Your son is having temper tantrums because he is not clear who the boss is. He thinks that if he yells and throws himself, he will get what he wants. In order to discourage this, you need to give him exactly the opposite of what he wants. I don't know what makes him have a tantrum, if you can be more specific, I can give you better advice. As a parent, you need to be in charge, not your child. If you don't get a hold of this now, the bigger he gets, the worse it will be. You can still physically control him at this stage, when he gets bigger you can't.
I read a book when I had my first child that tells you how to handle all kinds of situations. It is a short and easy read, maybe 100 pages. The book is life changing. It shows parents how to be in control without ever losing their cool. It tells parents how to get their children to obey immediately, without complaint and with a good attitude. They encourage parents to actually lower their voice if they have to repeat a command, instead of raising it. I only have 6 children because of this book. It puts you back in the driver's seat.
My 18 months old would fight me to get her diaper changed, and wouldn't want to get out of her highchair, and all other sorts of things to assert her will. Within 2 days, she was like a different child and I was a different parent. I read other parenting resources, but I never found answers like these.
You can view it here
http://stores.intellbaby.com/-strse-46/To-Train-Up-A/Detail.bokI wish you all the best!