•Human: Start at Goldshire and head East following the cliff face to the north of Crystal Lake. When you get the north of the Logging Camp head South. Follow the river to the border of Elwynn forest and Duskwood, then head North West back towards Goldshire (make sure you visit the two mines on this route). This route should net you about 30-40 copper ores.
•Night Elves: Your going to have to go to Darkshore, as Darnassus has no ores whatsoever! So start at Auberdine and head directly east until you reach the cliffs at the edge of the map. Now head south, hugging the cliff face as you go. When you get to the entrance of Ashenvale, head west to the coast and then North back to Auberdine. Head out from Auberdine, directly to the East (same as you did at the start of this route), but when you reach the cliffs this time head north. Just follow the cliffs to the North and back round the coast, heading South again to Auberdine. I find this figure of eight pattern to be easier than taking Auberdine in one whole route, but that’s just me. Feel free to improvise it. Normally get about 40-50 copper ores from this entire route.
•Dwarves and Gnomes: Ah, the home of mining and possibly the best place to start, Dun Morogh! You really don’t need a route around here, copper is everywhere, if you can’t find a decent route yourself, then you’re beyond help! But, I will tell you my favourite route. Start at Kharanos and head to the Wendigo cave (you all know where that is, right?). Clear cave and then continue on West, following the cliff face. Carry on until you hit the main road then head North up to the Frostmane Hold. From there head directly east over to Shimmer Ridge, then North up to Ice Flow Lake. Now follow the cliffs down to Ironforge, on to Misty Pine Refuge and back round to Kharanos. This run normally nets me about 40-50 copper ore.
•Another good run in this area is the Gol’Bolar Quarry. Circle the outside, around the top, then drop down and into the mines. I can get about 20 copper ores on this short run.
Mining 66 – 125
Mining Tin, Silver, Incendicite and Lesser Bloodstone
Estimated number of nodes to mine = 60
This part is a pain in the butt, if you don’t have a mount (well its all a pain in the butt, if you don’t have a mount) as the Tin Veins your going to need to mine are more spread out and not as common as the Copper you just being mining. You also stop getting skill up’s from smelting after about level 85 (Silver is the last thing to give you a skill up). The leg from 100-125 is also pretty bad, as Tin is green at this stage and therefore your getting skill ups at fewer intervals (just pray its a Silver spawn, instead of Tin, as this will still be yellow to you).
Horde & Alliance *even on PvP servers you can still use these routes and areas.
Easiest way to level up to 125, is to go to The Wetlands and find Thelgan Rock (its near the entrance to Dun Algaz - 53,64 for those with location add-ons). There is a cave there, that is full of spiders and a quest ore called Incendicite. This is an Alliance only quest, but Horde can still mine the ore. Now the ore itself is worthless and only used to complete the quest, but you can mine it from level 75 until about level 125. The nodes respawn quickly and you can level up your mining in less than an hour if your the only one in the cave.
If your Alliance and want to do the quest, go see Pilot Longbeard in The Military Ward in Ironforge for the starting quest. He'll send you to speak to Pilot Stonegear in Kharanos, who then gives you the quest.
Thank you to everyone who suggested this, especially Plog
Lesser Bloodstone: go to the cave in north east Arathi Highlands, just to the east of Hammerfall (path to cave is at 80,40) and mine the nodes inside. It's used as part of a quest chain that’s started in Booty Bay by Corporal Kaleb (in the tavern). You only need to keep four of them for the quest. Lesser Bloodstone requires level 75 mining