The talent system found in the backpack will give you one talent point every 4 levels starting from 30, so at 50 you'll have 6 points. I'd suggest the fury tree for dps and the... Valor tree? The one with evasion I forget the name, that one is good for tanking.
They're all relatively useful just consider what you'd need most for the fights you'll be up against.
You can always reset talents at the same place you'd reset attributes/unlearn skills. Each reset costs 1 mc per talent reverted, however that doesn't mean you can do them one at a time, i.e at 50 it would cost you 6mc to change your talents.