Flipguarder covered most of the basic ways to increase damage, but there's an important question you need to ask yourself: "What class do you really want to play?"
While I understand that you played a Warlock in WoW, you should never assume that just because something has the same name in D&D as somewhere else, that it functions the same. Warlocks in 4e D&D are Strikers (a role indicating that they focus primarily on dealing damage and getting around the battlefield), but they also have a lot of Controller attributes (meaning that they tend to focus on doling out conditions and interfering with the enemy's ability to do what they want to do). Among the Strikers, Warlocks are generally regarded as the lowest in terms of DPR (damage per round, which is pretty similar to the DPS that you're used to from MMO's). I never played WoW, but if you're familiar with Guild Wars then you can compare them to a Mesmer or a Curse Necromancer.
Now, if you're fine with taking some reduced damage dealing potential and getting some increased ability to basically say "F*** you" to enemies trying to do stuff, then by all means, go Warlock. They're great at that. However, if you're primarily looking to just deals tons and tons of damage, then take a look at the Warlocks much meaner cousin, the Sorcerer. Sorcs can still use things like Dual Implement Mastery and Implement Expertise to increase their damage dealing potential, but they can do so much more. They're resilient, and deals craploads of damage. Also, they have a single primary stat, which can make it easier to build one. You should check them out just to see if you like them, but by all means, feel free to go with Warlock as they're also an excellent class...they're just a little different is all.
As for Race/Class combos, that depends on which class you want to take and what build you're going with. Dragonborn make excellent Dragon or Cosmos Sorcerers due to their bonuses to STR and CHA, whereas Halflings can make great Wild Magic Sorcers due to their bonuses to DEX and CHA. Those races each have a bonus to a Primary and a Secondary stat for Sorcs, but there's lots of other options if you just find a race that has a bump to CHA and then just use points to get your Secondary stat up higher.
If you're gonna go Warlock, then you need to decide which pact, as that will determine your primary stat and have a big influence on which race you use. Fey and Dark Pact Pact Warlocks use CHA, whereas Infernal and Vestige Pact Warlocks use CON and Star Pact Warlocks use either CHA or CON depending on the power. Additionally, which pact you choose only affects what At-Will you get, your Pact Boon and what riders trigger on the powers...but you can feel free to take CON Star powers on your Infernal Warlock or CHA Dark powers with your Fey Warlock, or any other combination.
Half-Elves get boosts to CHA and CON, and so can easily go with any Pact. Tieflings, Dragonborn and Halfings get boosts to CHA, whereas Goliaths, Minotaurs, Dwarves and Wilden get bonuses to CON. Gnomes and Shardmind also get bonuses to CHA and INT (which is a secondary stat for Warlocks), and so can make excellent CHA based Warlocks. Really though, there's a lot of options.
