First go to http://www.dyndns.com/ and set up and account. (got to you'r email and validate etc then log in)
Second after clicking the confirmation link , log in and go to https://www.dyndns.com/account/services/hosts/add.htm
Third type in the hostname you want IE. DOomcloud.( I suggest .servegame.org)
Type you'r ip in then click CREATE HOST (CLICK NOTHING ELSE)!
Fourth Edit you'r config files to have you'r new hostname in it IE mine is Doomcloud.servegame.org
Put it in you'r realmlist.wtf and then launch you'r server
You'r friends can use the same name/hostname with their Realmlist.wtf EASY!!
Thanks leave rep++