I'll try to help as well, since I'm guilty of making a stupid thread about Lorestones.
Not all Lorestones can be found right off the bat. A few (like in Gorguath), require the "Detect Hidden" skill to be leveled up enough (level 5) to be able to find hidden doors.
Edit: Trainers; Each trainer can only be used once. Read next post for more info (thanks SpinelesS)
There are only five backpack upgrades in the game. Here are the locations:
Settlement: Gorhart, Odarst
Trader: The Corner Shop, sold by Rikka Egest
Settlement: Rathir, Upper City, Tywili Coast
Trader: Scholia Arcana Main Hall, sold by Wil Donell
Settlement: Ysa, The Sidhe
Trader: Asker’s Alley, sold by Riona Helt
Settlement: Domus Politica, Adessa
Trader: Senecer Macit
Settlement: Mel Senshir
Trader: Illyn Doldran
Last edited by Mercury; 02-16-2012 at 03:52 AM.