Skinning 1-450

Level 0-75 (Dun Morogh):

Remember to put on your gloves with +5 skinning and head over to Ironforge. Go outside to Kharanos and just beneath (South) there is a cave full of yeti's. I love yeti's, you can gather up about 6-7 at a time and they still spawn right on top of you. We wan't to skin these mobs all the way to level 75. (Takes approx 10min)

Level 75-150 (The Barrens & Southern Barrens):Go back to Ironforge and learn the next rank of skinning, talk to the flight master and fly to Wetlands. Take the boat from wetlands to Theramore. Now go towards crossroads and take a right allmost down to Ratchet. (East of crossroads). When coming from crossroads towards Ratchet, you will see packs of Savannah Prowlers just chilling out in the bushes. Gather up these (Can easily gather up 6+ at a time) and skillup until approx 120-130. I prefer doing these to they're grey because the next part is a little bit slower.

Level 150-225 (Hillsbrad foothills & Badlands):
Go back towards Theramore but notice the Stormshout kodo's south of Camp Taurajo. Kill these, i managed to gather up about 4-5 at the same location. They do patrols too, so eventually more will patrol over your skillup-skinning area. Continue to skill up here until you are level 150.

Go back to Theramore, take the boat to Menethil, and fly to Ironforge. Learn the next rank of skinning.
Fly to hillsbrad foothills, and go to the Yeti Cave north of Southshore. Approx at the very middle of the map.
I still love yeti's, same thing as the first yeti cave, these guys spawn fast you eventually you will have about 10+ mobs at the same location to skillup. Notice a few of them are red at the beginning, but don't worry, in a few skillups they will become orange. You will skill skinning all the way up to atleast 210 in this cave.

Fly back to Ironforge, learn the next rank of skinning. Fly to Loch Modan, and go to badlands. Find a nice location for the wolfs here (They are pretty much all around) and skill these up to atleast 250.

250 - 300 (Blasted Lands)

Use your hearthstone again to Dalaran and use the portal to Stormwind, fly from here to Blasted lands. If your hearthstone is still on cooldown, just go to Loch Modan and fly directly to Blasted Lands.

Find the hyenas here, i managed to gather up a pack of about 6 mobs at 48.21. They spawn quite fast and also have "patrols", hyenas with extremely long walk paths. Eventually you will have about 7-8 before you are finished.

300-375 (Outlands, Hellfire Peninsula & Nagrand)
In outlands, skinning is nerfed. One mob have 1/5 chance to give skillup, so prepare to use a LITTLE longer time here.

Go directly to the portal to Outlands. Fly to Honor Hold and learn the next rank of skinning. Go outside and find the boars there. Doesn't matter where actually, they are everywhere. I managed to get a pack of 5 at the beginning, the more and more spawned around me and i ended up on atleast 10. Skill these up to atleast 340.

Go back to honor hold (or temple of telhaamat if you are closer) and fly to Telaar in Nagrand. Go north towards the Nesingwary camp and find kodo's and stags around in this area. They can both be skinned, but the kodo's are very big so watch out where you kill it. They might fall on top of another mob you are going to skin, wich sucks.

375-450 (Borean Tundra & Sholazar Basin)

This is probably as fast as 75-150. Hearth to Dalaran and fly to Borean Tundra. Learn the next skillup. Eventually sell some thrash to vendor. You know those Mammoth's walking around with their babies? Great. You can get a pack of 100 if you want to here! You can even loot Arctic Fur of these guys when you skin, wich sells for 70+ G on most servers. Anyways, skill these guys up to atleast 425. Eventually, you can skin these up to about 440 but i recomend going to the next zone.
Go to Fizzcrank Airstrip and fly to the nesingwary camp in Sholazar Basin. Go to the east of Frenzyheart Hill and gather up those Apes/Gorillas here. They are also great, and they also drop arctic fur.

Congratulations, you are now a grand master skinner, in approx 3 hours!