'''TLDR''' My hunch so far is to cover all the basic, fairly common skills that show the rich content in the game, without spoilers. As a general rule of thumb: if the skill comes from a high level dungeon, requires slaying difficult foes, and what not.. I would link to it from within the parent article (the dungeon, zone, or NPC) but not on the front page. This gives some room for new players to explore and discover on their own. Once a player found such a skill of course, it's really easy to look it up either in game (/wiki) or via search here.