How do i make a server easily?

Hi, I was wondering how to make a server that me and my friends can play on.

I just want to make an easy server that is free and good. I tried to watch some youtube videos. But, the stuff they do on the videos....seems to harmful for my computer. Someone said what you would do is download a minecraft.exe thingy from minecraft.net and download hamachi. Is hamachi dangerous? Does it download virusess to my computer?

I'm not computer savy. So speak english please. I hope your suggestions help. And thanks.