If you are take Skinning and Mining as your main professions,i will take these as world of warcraft gold making guides.The world of warcraft gold making tips are followed:
Skinning
Skinning, the only way to powerlevel is just killing mobs and skinning them. I picked it up from the beginning, so I can't say how long this will take.
Sell your stuff on the AH. It will sell. Set a buyout. If there is still time to go before prime-time on the server ends, set the listing time to long. If it's almost over, go ahead and splurge on Very Long.
Mining
Mining. THIS is a world of warcraft gold maker, and I'm sure some people are going to bitch about me revealing one of the very good mithril spots, but here we go:
I took this up at 30, and spent around 6 hours powerleveling it up to 230. As per usual, sell the stuff on the AH in smelted stacks. BUYOUT is your friend. It is the BEST thing you can do.
For getting through the copper levels, Durotar is your friend. Sorry about this for you alliance guys, but for copper and tin, you're out of luck for my advice.
The stuff is everywhere. I did a sort of lazy figure eight around the canyon right before Ogrimmar. Took me about 45 minutes to get up to tin level.
Tin is a bitch. The Barrens had the easiest route to go on, but it took a long time compaired to the other levels. Near Ashenvale there is a place with some harpies that has a fairly good tin spawn rate. From there, stick to that wall, and go south. There are spawns along that, but your goal is South Barrens. Go in circles around the Scorpid and Bristleback and Razormane areas. After a while of this, you should eventually get up to what's need.
Note: When selling on the AH, it isn't always the best idea to just smelt copper and tin into bronze, or visa versa. Check the going prices, and figure out if selling the bases or the product will sell for more. I've seen Tin going for 70s a stack and copper for 40s, while bronze was only going for 50s a stack. You lose 10s when you sell bronze.
Iron is easy, but a bit time consuming. The easiest route to just go around over and over again in is in the Shimmering Flats area of 1000 Needles. A little dangerous for alliance people, but it's still a nice round circuit. Go around the edges, and there are spawns. It also spawns veins in the middle of the little lake south of the racetrack.
Mithril is your world of warcraft gold maker. Engineering and Blacksmithing both need massive quantities of the stuff, and it sells fast, and for a fairly high price. One word: Tanaris. You could travel around the whole thing, but I've found it much easier to start at Gadgetzan, and cut across the desert to the start of the bug area, checking all of the little rock outcroppings on the way.
This place is dangerous, and I even die some at 45+, but there are alot of spawns here. Travel along the edge, and then back along the outter boundry of it, and then continue on circling the map. There are alot of spawns in here, and their value shows in the defense the mobs put up. I'm not going to lie to you, it'll be hard to live consistantly here without a mount or travel form. Thistleshrub valley also has a few, and then another bug area on the edge of Un'Goro crater. There are also one or two by Zul'Farrak and the area close to Gadgetzan. They don't spawn as often as the others do, though.
As for Thorium... You'll see some in Tanaris, one spawn in Thistleshrub, and another by the level 54-61 elite dragons at the Caverns of Time... But if you want to find reliable spawns, you'll have to ask someone else. I don't know of any that aren't impossible to get to until 50+.
