The red is health. The yellow bar is your stamina, You can run until the bar empties. When this happens, you are forced to walk, until it charges back up some. To the right of the stamina bar are four small boxes, which is your belt. The belt allows you to quickly access potions and such.
Some belts are bigger than others, which can hold more.
Right beside the two globes, you see two boxes, one red, with an arrow. Overall, the layout is pretty easy to get used to. There a lot of keys bound for quick access to potions and spells, which if used, can help a great deal when you are in the heat of battle without time to pull up each screen. The game is awesome and highly addictive. The gameplay, especially multiplayer, is very fun.