1) When you enter the Training Arena, you will see a list of duels on the left. Blue duels are ongoing, while yellow duels are open. You can click on a yellow duel to join.
2) On the right there is a list of all the other Iczers in the room. Click on them to bring up their info.
3) In the center of the screen is the info area, here you can look at your Card Files, check out your stats, or look at the stats of other Iczers in the room.
4) On the bottom of the screen is a local chat area, where you can talk with others in the room. If they are in the middle of a duel they will not see the local chat window, so you'll have to use the chat client to talk to them instead.
5) You'll notice a drop-down menu above the list of active duels. This is where you choose the Card File you'll being dueling with. Just highlight the one you want and hit SELECT to choose it.
6) When you're ready, join a Duel Room or click on Make Room to make your own, and wait for a challenger. You can set preferences here, such as the level of opponents you'll face, and whether or not you want to let other players watch your duel.
7) You can also click on Random Duel, and you'll be paired up with a random opponent or a random open Duel Room. If you click on Random Private Duel, you'll be paired up with a random opponent who also does not want to allow others to watch the duel.
8) The Single Player Arena works just like the Training Arena, except the NPC rooms are always available and they are colored white. Just click on one to join. There is no duel spectating in the Single Player Arena, and you don't need to make Duel Rooms.
9) The other Arenas work just like Training, except you don't have access to the local chat or the Iczer list..