How to make a free small minecraft server?

You can find several helpful videos on youtube showing how to create a server + portforwarding so if your looking for a server for the latest mc update (1.7.4) then look up on youtube How to make a minecraft 1.7.4 bukkit server + portforwarding tutorial

There are lots of tutorials on hosting your own minecraft server on Youtube however it is not a good way purely because it relies on your computer and internet to host the server. You will need to go through the hassle of port forwarding so other people can join, your computer will have to be on with the server running for anyone else to join so it won't be up 24/7. I highly recommend paying for a site to host it for you, I lately started my own server with https://www.prominecrafthost.com which offer very cheap packages. Also not only do you host your own vanilla minecraft server you can also host things such as Tekkit, Hexxit and Feed The Beast.

Here is a very simple and detailed guide. It would take a really long time to explain what to do on here.

Also, when you get to the portforwarding thing, make sure you portforward your IPv4 address and give your friends your external IP address (search on google "What is my IP" and it will show it)