To effectively interact with WoW virtual world one of the most important aspects is to have your action bar properly set..
Placing the spell or other skills correctly in the action bar can mean the difference between succeding in a quest or encounter or to fail.
You can have up to 7 sets of action bars active at all times in your screen.
The following graphics will explain how to set your action bars.
The first part is to set the action bar interface correctly so all bars can show in your screen.
The second part is to refine which icons from your spellbook you want to place. As a word of caution, you dont want to place icons of actions you dont perform regularly. Those can go to action bar #2, examples of those are: cooking, first aid, profession icons, etc.; all you have to do is switch at the action bar arrows at the center to access it.
An icon you want to have in action bar #1 is the main mount you use the most. Been able to mount rapidly will either allow you get out of an unwanted situation fast or to perish. A suggestion is to place in the last icon place in action bar #1.
By default in action bar #1, melee attack is always 1 and ranged equiped weapon such as a wand or gun is 2. Next to it you may want to place a spell you use for range attack if you have them, e.g. Frostbolt for mages
If you have a question, let us know and we will prepare a graphic to explain it better.