Your armor question makes me think that you haven't visited the wikis. We have two available
http://guildwars.wikia.com/wiki/Main_Page
and available in-game through F10 or help on menu or /wiki in chat bar
http://wiki.guildwars.com/wiki/Main_Page
Your armor reaches a max level fairly quickly except in original Guild Wars (Prophecies) where you have to get a run to Droknar's Forge from Beacon's Perch to get max armor early.
You haven't said which of the campaigns you are playing. Higher population places are
Guild Wars - Ascalon City, Lion's Arch, Droknar's Forge
Factions - Kaineng City, The Marketplace, Lutgardis Conservatory (HFFF)
Nightfall - Kamadan, Sunspear Sanctuary, Remains of Sahlahja (Lightbringer/Sunspear point farming)
Eye of the North - most towns/outposts have fairly high population
wiki page for Elite Missions
http://wiki.guildwars.com/wiki/Elite_Mission
wiki page for Dungeons
http://wiki.guildwars.com/wiki/Dungeon