Do you want to make a Death Knight in World of Warcraft’s Wrath of the Lich King expansion? I’ll cover a few things that are basic and important to the Death Knight that you should know before starting one. First in order to make one you must have a level 55 character on that realm, not account. You will start off above Eastern Plaguelands and do a series of starter quests that will get you most of what you need, including your death charger (mount), and gear specific to your talent tree.
Death Knights use ruin power to generate power for abilities. It builds up under your health bar like rage does for warriors. There are three types of ruin power: blood, frost, and unholy. Each of these is also the name of the talent trees. Death Knight abilities require a rune of blood, frost or unholy to activate and are displayed under your character portrait.
While everyone will argue what is the best talent spec for each given situation they do have a basic break down. The blood tree is mainly for grinding and dps. It holds most of the abilities that increase damage and restore health from hits. Frost is the tanking tree giving more threat generation and damage reduction. Lastly the unholy tree is for PvP by increasing attack speed and reducing the death knights cool down abilities.