Resto bar: Healing Springs, Harness Magicka, Combat Prayer, Enchanted Growth, Inner Light, Northern Storm
Destro bar (buff / debuff bar): Elemental Drain, Lightning Blockade, Budding Seeds, Energy Orbs, Expansive Frost Cloak/Purge/Betty Netch, Aggressive Warhorn
If you run Master Architect you might wanna change one of the Ultimates for Enchanted Forest. And you have to swap for example Frpst Cloak out for Purge on first boss vHof.
For first healer roll a templar. You can't beat BoL.
Terrible advice.
OP specifically asked for tips on skills for a Warden, not whether or not he should roll a Templar or not.
I recognize the fact that Templars are still regarded as the best healer in the game, but the Warden is a close second if the player has the correct rotation.
Skills a typical Warden healer would use that every class can use:
Springs (accessible to every class)
Combat Prayer (accessible to every class)
Healing Ward (accessible to every class)
Rapid Regeneration (accessible to every class)
Warden-specific skills:
Budding Seeds (burst heal)
Enchanted Growth (burst heal)
Leeching Vines (good when taking damage, can apply to anyone)
Lotus Blossom (every time you light or heavy attack someone gets healed)
Healing Thicket (ultimate, massive, massive healing over a 6-10 second duration in an 8 meter radius)
Naturally there's more to it but these are some skills that the Warden Healer would use.
And as you can see, 4 of them are skills found in the Resto Tree, accessible to anyone. And about the passives, the Warden has a reliable source of Major Mending UNLIKE the Templar.
So in conclusion, why should Op re-roll a Templar when a Warden can get the job done with the right skillset, intelligence and setup?