Where can i find minecraft servers? How do i make my own?

I've only been on one minecraft server before, my mates and its a creative mode game. He said that it costs to keep running and i have to pay if i want admin. But i won't because i can't stand creative mode it takes the fun out of everything you can do on there. My 2 questions are: do servers cost and if not how do i make one, and does anyone know any good survival servers i can join and hopefully have fun in? I'm a zombie survival building fortresses type of guy.