The first mining you will do is gathering copper and rough stone from copper veins. The place I have found the most frequent copper spawns in lower level areas is near Kharanos southeast of Ironforge. The Grom Bolar Quarry almost always has its share of copper if you can face the lv 8-9 troggs that infest it.
My Gatherer Addon keeps track of all the minerals I mine and marks them on the map. You can check out Gatherer HERE.
I have also found the best concentration of copper and tin together in Loch Modan. This is more in the lv 15ish range. I will post the locations when I post for tin.