from utilizing the search feature:
Quote:
Ooze Covered Truesilver Deposit
Feralas, Silithus, Un'Goro Crater
Truesilver Deposit
Alterac Valley, Azshara, Desolace, Dustwallow Marsh, Felwood, Feralas, Silithus, Stonetalon Mountains, Tanaris, Thousand Needles, Un'Goro Crater, Winterspring, Alterac Mountains, Arathi Highlands, Badlands, Blasted Lands, Burning Steppes, Eastern Plaguelands, Hillsbrad Foothills, Searing Gorge, Stranglethorn Vale, Swamp of Sorrows, The Hinterlands, Western Plaguelands, Blackrock Mountain, Maraudon, Uldaman
You might also take up alchemy and transmute Mithril to Truesilver, or have a friendly alchemist do it for you (48-hour cooldown per bar).
but... the very best place to locate truesilver is the AH...