I really want to know where some good ones are and I'm too lazy to look it up. I only found a really good orichalcum mine. Its called bilegulch mine and its south and a bit west of fort sungard. Its a bandit camp also so be prepared.

Gloombound - Ebony
One at Kynesgrove - Malachite
Blackreach - Soul Gems & Corrundum
Halted Stream Camp - Iron & Transmute Spellbook

Darkshade Copse has gold ore veins. One outside the entrance to the cave, I think, and at least one more inside. Maybe two. I can't remember exactly, I was a little distracted by the numerous trolls that were trying to eat me at the time.

Kolskeggr Mine is a great source for gold ore. It has 17 veins inside an a couple random ingots/ore pieces. I only recall that one because I'm trying to fill a spare room with gold ingots.