Wardens will naturally be more tanky than a Shade or Ranger. Their spells are focused on self-healing and tanking large groups of monsters at once.
They will want to focus into either Agility or Strength, Endurance and some Willpower.
Valuable talents to get are "Arcbolt", "Whirl" and "Road Less Traveled", these will give someone a large chunk of Willpower at low cost, saving them stat points for more Strength OR Agility and Endurance.
Lifeblood and Mountain's Fortitude are also good pickups for Wardens having problems with ranged monsters.