Updated 12/2/08, updated text in bold italics
This is part 1 of an ongoing guide that will later be compiled into one large "uber-guide" for up-and-coming Death Knights.
Tarmr is only level 58 at the moment, and still slowly completing his gathering profesions to 300 before venturing into Outland, so some specifics may be revised over the course of his adventures.
This guide is intended for starting Death Knights and will not cover advanced tactics, in-depth stat values or end-game min/maxing.
I'll spare the backstory. I assume everyone knows that Death Knights are the game's first Hero Class, etc. Plate, 2-handers, dual-wield, blah blah blah.
Roles
Death Knights are capable of tanking, damage dealing and PVP, regardless of talent spec. Do not listen to anyone who tells you otherwise. This is a new design direction for Blizzard. Your spec will not determine your role, but rather HOW you perform it. Of course, some builds will be optimal in certain situations.
Here's the general breakdown.
Blood Knights will have very high, sustained damage against single targets, as well as increased survivability and group utility through healing mechanics.
Frost Knights offer the best mitigation against melee attacks, very high, bursty, crit-based damage potential, limited AOE and extra Crowd Control. Frost is probably the "best" tanking spec. Also, Death Knights looking to Dual-Wield will most likely want a Frost-heavy build.
Unholy Knights are best at AOE attacks, diseases and magical defense, as well as pet usage. Unholy Knights also gain speed increases that will pay off in PVP.
Resources
Death Knights use 2 different resources, Runes and Runic Power.
There are 3 basic types of Runes.
Blood
Frost
Unholy
There are also special Death Runes.
Runes are used up by various spells and then recharge after ten seconds. For example, Blood Strike will use 1 Blood Rune, while Death Strike will burn 1 Frost and 1 Unholy. This gives the Death Knight a playstyle similar to Rogue, with the ability to be at "full power" at the beginning of an encounter, then using skills and quickly recharging to fire them off again.
Death Runes are granted by certain talents and will take the place of the other Runes. Death Runes are "wild cards" and can be used in the place of any of the basic three.
Runic Power functions almost identically to a Warrior's Rage mechanic. Each skill that the Death Knight uses that consumes one Rune grants 10 Runic Power. Two Runes grants 15 and three Runes grants 20. This can be increased via talents. Runic Power can then be used for attacks. For example, Death Coil is a basic Death Knight ability that can only be used once the Death Knight has accumulated 40 Runic Power. Just like Rage, Runic Power degenerates over time outside of battle.
This is what makes the Death Knight a Hero Class. They are no more powerful than any other class, but rather, are more difficult to play and thus not suitable for beginners.
Presences
Presences are what allow Death Knights of all specs to excel at each situation they find themselves in. They function much like Warrior Stances or Druid Forms.
Blood Presence is for basic damage dealing and excellent for soloing thanks to the healing effect.
Frost Presence is the default tanking Presence.
Unholy Presence is geared more towards PVP. However, with the increased attack and casting speed, it may be able to outpace Blood Presence for damage over a short period of time. However, after blowing all your skills with reduced GCD, you will still have to wait for Rune cooldowns.
Part 2: Spells
