Very easy to find any class AQ, but for the necro....you need to goto East Freeport and enter the scribe shop that is on the area map. Go into the back of the shop (on the same level) and hail a gnome called Kirsteh the Witch. As long as you have finished your class quest and reached 20+ she will give you the armour quests, starting with the gloves and progressing from there. AQ1 is based around Ruins of Val'Marr, AQ 2,3 are in Fallen Gate, AQ 4 is in Serpent Sewers and AQ 5, and 6 are completed in Nek forest.
Hope this is useful
Pudissy 40th Necro Splitpaw server