To enable players know more about Guild Wars, VCSale.com provides combat guide as follow:

Combat
Combat is a way of life. Master the basics of fighting before you jump headlong into the game, or risk a premature trip to the afterlife.

Come Equipped
Before you enter a mission or explorable area (in other words, before you leave town), load your Skill Bar with the eight skills you think will serve you best in the coming conflict. At the start of the game you'll have empty space, but as you learn and Guild Wars Gold  earn more skills you'll need to be selective in how you equip your character's skills. Your hero's armor (courtesy of your primary profession) is already equipped—make sure your chosen weapon is at the ready and that any alternate weapons are loaded onto the quick weapon menu (keys F1-F4).

Equip Weapons
Equip weapons and Guild Wars Gold  armor from your Inventory, which manages the items you have acquired. Double-click on a weapon or piece of armor in your Inventory to equip it.

Fighting Creatures
Virtually anywhere you travel outside the safe confines of a town, you are likely to encounter hostile creatures that will happily eat you and/or your party for lunch. This kind of combat is referred to as PvE (for Player vs. Environment) or PvM (Player vs. Monster).

Targeting Enemies
To quickly target and Guild Wars Gold attack the nearest creature, press Tab to highlight an enemy, and then press Space to attack. Tab targeting allows you to cycle through the enemies that you can see on your compass. To reset the cycle you can press the \ key to re-target the closest foe. This is useful when you are involved in an especially intense melee—enemies move around while you're fighting them, and if you only use the Tab key you might unintentionally target a distant foe, thus drawing more hostiles to your location before you and your team are ready to deal with them.

Targeting Allies
You can target allies by clicking on the ally's name in the Party menu or by selecting the actual ally. When you've targeted a friendly, you can perform various actions on them. You can heal allies, open a Trade window (by clicking the Trade button at the top of the screen), and Guild Wars Gold  follow the ally by hitting the Space Bar (note that once you catch up to the ally, you will need to hit the Space Bar again to keep following). The follow command is useful when a group leader is guiding others through an unfamiliar area.