It doesn't matter so much for Holy Paladins, being more of interest to Ret and Prot Paladins but here is a break-down of how it works, with Holy-specific information beside it.
Holy Power is somewhat similar to Rogue combo points in that they build up over time if certain abilities are used, to a maximum of three charges. For Holy Paladins, these points are generated by Holy Shock and, if you have the talent Tower of Radiance, direct healing the target of your Beacon of Light.
You can use these charges to enable or boost some skills. Holy Paladins would be most interested in Word of Glory, an instant heal that heals for some total based off how many Holy Power charges you currently have.
This mechanic is a lot more useful for Ret Paladins, who I think it is mainly aimed at. They can charge it using Crusader Strike (for a guaranteed change) or, if they have the Divine Purpose talent (which they should), have a 40% chance of getting charges from just about any Ret skill, i.e. Judgement, Exorcism, Templar's Verdict, Divine Storm, Inquisition, Holy Wrath and Hammer of Wrath. They can then use it to charge their Divine Storm (AoE damage), Templar's Verdict (single target damage) or Inquisition (holy damage boost), or Word of Glory if they want/need a quick heal.
Prot gains Holy Power from Crusader Strike and Hammer of the Righteous, and mainly use their charges on Shield of the Righteous, though Word of Glory is obviously also an option for them as well for a quick self-heal.
They won't delete your characters -_- after you lose your starter edition when your days expire your account gets freezed and you can't log in until you pay again.
You can buy battlechest if it is cheaper in your region...but you activate one by one as you play.I would buy one by one since old expansions get cheaper and cheaper with every expansion they release,and if you get bored in middle you can quit without spending money on all expansions.
- You play until lvl 25 (Free)
- Use WoW trial 10 day (should be on Battlenet page)
- Buy WoW original (you get 30 days with it)
- Buy 60 days key to get lvl 60 (if not already)
- Use Burning crusade 10 day trial (should be on Battlenet page)
- Buy Burning Crusade + 60 days
- Use WoTLK 10 day trial (should be on Battlenet page)
- Buy WoTLK + 60 days
- Cataclysm 10 day trial (should be on Battlenet page)
- Cataclysm + 60 days ...
Use your 10 day trials when you reach max level,before that use 60 day keys as needed.
Best Answer
It says your artifact is at full power because Blizzard recently made a change that gives everyone 127 ranks in their artifact, ramping up over the next couple of weeks until the Battle for Azeroth prepatch is available.
However, to unlock this for a class, you need to have done a quest with Magni onboard an air ship of your faction in Silithus. To get this quest, in addition to the rest of the Silithus quests, you also need to have done the quest with Magni in Sholazar Basin. If you haven't done this quest yet, go do it now, then log out and back in. A new quest should appear to empower your artifact, giving you 127 ranks in each of your artifacts. You might have to actually open your artifact trait window by switching specs and shift-right clicking.
After you have unlocked this quest, artifact power no longer is usable and you can safely vendor all artifact power tokens you receive. Your artifact will gain new levels on its own, up to max Concordance rank (which should be 100).