Step1
Travel to Chillwind camp in the Western Plaguelands. Make sure your character is at least level 49.
Step2
Talk to the Argent Dawn representative and acquire the Argent Dawn Commission. This trinket allows you to find Scourgestones on undead in the Plaguelands, Stratholme and Scholomance. You must be wearing this trinket to find Scourgestones.
Step3
Begin killing undead. The best place to start is in the Sorrow Hill graveyard. Kill Skeletal Flayers and Slavering Ghouls until you rack up 20 Minion’s Scourgestones. Keep any Bone Fragments you find. You will need them later and they will net you lots of xp!
Step4
Take your Scourgestones back to the representative and exchange them for an Argent Dawn Valor Token. You can use valor tokens to gain reputation points with the Argent Dawn, but it is not in your interest to do this now. Just stash away the token and return to it later.
Step5
Continue killing undead and accumulating Scourgestones--20 Minion’s Scourgestones can be repeatedly exchanged for a valor token.
Step6
Accept the quests to attack the Cauldrons when they become available. There will be four of these missions. Not only are they good experience, they open up later quests and give you the chance to grab some Invader’s Scourgestones. These can be exchanged for Valor Tokens at a rate of 10-1 instead of 20-1.
Step7
Finish the Cauldron quests and continue grinding Sorrow Hill. This is the easiest and safest place to grind Argent Dawn reputation.
Step8
Venture east to the Eastern Plaguelands when you get either a quest or hit level 52 or 53. You may want to strip your armor and ride naked; your gear can take a beating on the road and leave you with a big repair bill.
Step9
Travel east along the road through the Eastern Plaguelands until you come near a village or you see large abominations wandering around. This means you have reached Corrin’s Crossing. DO NOT RIDE THROUGH IT! To do so is suicide! The mobs here are very high level, elite and extremely unpleasant. Head south of Corrin’s Crossing until you cannot see the town anymore, then continue east.
Step10
Travel directly east of Corrin’s Crossing, and you should eventually hit the Argent Dawn bastion of Light’s Hope Chapel. This is a safe place to rearm and rest. You will find a multitude of quests here, including one that allows you to turn in your Bone Fragments.
Step11
Venture into Stratholme and Scholomance when you are level 58 or higher. Running either of these will greatly increase your standing with the Argent Dawn. Just make sure you have a large, experienced party and your Argent Dawn Commission with you.
Step12
Once you are halfway through Honored, begin using your Valor Tokens to gain reputation. Why wait? Because until you hit the halfway point of Honored, you can still gain reputation by killing the skeletons and ghouls at Sorrow Hill. After that, you can gain reputation only by using Valor Tokens or running Stratholme and Scholomance.
Step13
Once you're friendly with the Argent Dawn, you can buy a few items from the Supply Officer at Chillwind and Light’s Hope. For Paladins, you will want to invest in some of their Enriched Manna Biscuits; you will need 20 to obtain your epic mount, the Charger. The Supply Officer offers better gear as your reputation increases. Eventually, crafting plans will open up that are some of the best to be found. While the gear is expensive to make, it sells well.
Step14
Take a look around Light’s Hope and note the people who have quests. Some of them offer repeatable quests that require you to bring in 30 of a certain item (Bone Fragments, Savage Fronds, Dark Iron Scraps, Core of Elements). Do these as often as you can. They reward you with either an Insignia of the Dawn or an Insignia of the Crusade (referring to the Scarlet Crusade, which maintains a small contingent of officers at Light’s Hope). These Insignia can be used to purchase excellent gear from the Supply Officer. As your standing with the Argent Dawn increases, the number of Insignia needed to purchase gear decreases. If you are impatient, consider grinding your reputation first--it's much faster than accumulating 60 Insignia for the Superior Armaments or 240 Insignia for the epics.