First you need to download the server creator and mod installer by edmiester777 (i have nothing to do with this program but is extremley helpfull) and hamachi so no port forward required! Next you run the server maker and choose which server you would like. Bukkit is harder but more popular and more rewarding in the end. vanilla is less popular but is the easiest to make, it's your choice.
Next sign up for a hamachi ID and it will give you a IP adress, you will use this to run your server on. Next you choose your plugins if you do bukkit or just run it if you do vanilla. Now move the files it created into a new folder and run start.bat 1 and it should generate files.Then go into server properties and add your hamachi server IP into the IP slot.You can add your world if you want.Next run start.bat 1 again with minecraft up. add your sever IP into minecraft and you should be on your server.

If you want people to join they have to have hamachi and have your ID and password for hamachi to join your personal network.