Priest Leveling Guide is divided in two major: Holy Priest and Shadow Priest. Depend on your choice, the build and leveling style will be entirely different. As for this guide, it will focus on Holy Priest Leveling Guide by describing the priest talent builds.
If this is your first time playing a priest, know that there are few type of Priest: "Holy Priest" which is your conservative healing-focused Priest and " Shadow Priest" which is focus on deadly skills.
Priest Talent Builds
First, you will want to invest on Healing Focus and Improved Renew. Put two points in Healing Focus and 3 in Improved Renew; it is important that you can heal more without interruption.
The next things to do is maxed Spell Warding and Divine Fury to prolong your life. Add one point to Desperate Player, it will heal you instantly, also another skill to prolong your life.
Maxing Holy Reach will give you 20% extra range for six different spells, keep you in safe distance while maintaining the survivability of your group members. Improved Healing is need to be maxed as well since it will reduce the mana cost for five different spells.
Healing Prayers is another friend of your mana pool, max this talent to gain 20% reduction of two different spells. As for Spirit of Redemption, you don't want to use this often since it will make you die, but one point in this talent can save your group from a chaotic situation, so take this one as a reserve.
Obviously, you will not be the damage dealer when you are in a group, but adding 5 points to Spiritual Guidance is not a bad idea since it will give you fighting ability for unpredictable situations.
Different Priest Leveling Guide suggest different approach for Surge of Light; if you are planning to use Smite and Flash Heal a lot at higher level, take this talent, otherwise just leave it. As for Spiritual Healing, you definitely want this as a Holy Priest since it will increase your healing spells by 10%.
A Lightwell will benefit the entire group during a raid; it heal anyone in your group that click it. The healing will takes time, but it is good to preserve your mana and time.
Put two points in Empowered Healing to boost your greater healing and three in Serendipity to reduce your next spell casting; these will open the next talents.
The next three talents are crucial for a Holy Priest and you need to max them all. Empowered Renew will make your Renew heal the target instantly; Circle of Healing allowing you to heal up to five friendly party or raid members within range; Test of Faith increase healing rate on a party members whose health below 50%, increase the probability to save him/her.
These two last talents have many variation in different Priest Leveling Guide, some will say to invest the rest of the points in the Discipline Tree, but for this build, I will include it as well. Put three points in Divine Providence to gain access to the next talent; three points will give you 6% boost in some healing spells. As for the last talent, Guardian Spirit; it will increase your tank's survivability and make it easier for you to keep him/her alive during chaotic situation.
As a Holy Priest, you will want to spend the last 20 points on the Discipline Tree to increase your survivability. Keeping yourself alive comes first before maintain the others health and a group will be in a very disadvantage when their healer dies, so these are how to spend the rest of your points:
Unbreakable Will; reduce the duration of various side effects, enable you to back into battle faster.
Silent Resolve; reduce the chance to dispell your helpful spells and damage over time spells.
Improved Power Word: Fortitude; increase Fortitude and Prayer Fortitude by 30%.
Martyrdom; gain Focused Casting effect for six seconds after getting hit by critical range or melee attack.
Meditation; allow your 50% of your mana regeneration continue even as you casting spells.
Inner Focus; reduce mana cost for the next spell by 100% and increase its critical rate by 25%.
Improved Power Word: Shield; increase Shield word by 15%.This priest leveling guide is focus on priest talent builds; as for leveling places you can visit instances dungeon with your group or leveling through quests. Doing quests is more recommended since it will earn you proper gear so you don't have to bought it and it is faster to reach level 80.
