Healing Touch - Heals a friendly target for X to Y. This is the Druid's main healing spell. You can only use this ability while you are in Druid form. There are times where you should have two levels of this spell available on your action bar to use based on how damaged the target is. You don't want to waste mana by using a more powerful heal than is necessary.
Rejuvenation - Heals the target for X over Y seconds. Rejuvenation is good to have active during combat. That way when the enemy is causing damage, you are healing during that time and mitigating some of that damage. If you or a party member is slightly damaged after battle, you can cast Rejuvenation to help heal the damage. Rejuvenation is also useful to cast on tanks that are pulling monsters.
Regrowth - Heals a friendly target for X to Y and another X over Y seconds. This spell is a mix of a heal and a heal over time spell. Regrowth takes a while to cast so you don't typically want to use it on yourself when you're being attacked. This spell is useful after battle or for casting on party members who are damaged but are not taking significant damage. Otherwise you will want to switch to Healing Touch instead.
Innervate - Increases the target's Mana regeneration by X% and allows 100% of the target's Mana regeneration to continue while casting. Lasts Y sec.
Tranquility - Regenerates all nearby group members for X every X seconds for X seconds. Druid must channel to maintain the spell. If a monster interrupts this spell it will cancel. This ability would be best used when multiple party members need healing at once.
Rebirth - Returns the spirit to the body, restoring a dead target to life with X health and Y mana. This spell requires a reagent.
Mark of the Wild (Powerful Buff!) - Increases all friendly targets' armor by X. At higher levels this spell adds an increase to all attributes. At even higher levels this ability also adds an increase to all resistances. This is one of the most powerful buffs in the game, making a Druid a welcome addition to a party.
Gift of the Wild (loot drop) - Increases party member's armor by X, all attributes by Y and all resistances by Z for 1 hour.
Cure Poison - Cures one poison effect on the target. Another welcomed ability when monsters are poisoning you.
Abolish Poison - Attempts to cure one poison effect on the target and another poison effect every X seconds.
Remove Curse - Dispels X curse(s) from the target. This is a welcomed ability as no one likes to be cursed!