I have found a beautiful blog which talk about Suse Linux in French. It explain all basic and is great for newbies.
Thanks to this great blog, I have found a second great site named www.Kameleon-facile.org which can generate a script to add all repository easily!!
This script is generate for smart but you can just modify a little it for Yast by adding “zypper sa <URL> <name>” where URL is the URL you have and name is the name you want to attach to this repository.(Paid attention to have name in one word)