Start with level 10 mobs around Elwyn Forest and just get your skinning up. While you're working on your skinning you'll be getting light leather to start to building leatherworking. When the word 'Skinnable' on the corpses turns green, move up to mobs that are between like lvl 15 and your lvl in westfall. From that point on just stick to the mobs around your level. You're only 18 you're really not that far ahead and dont have THAT much catching up to do. I had 50/300 skinning at like lvl 30, and even that only took me like an hour or two to catch it up to the level it should've been at 30. Bottomline, skinning is one of the easier skills to catch up if you're behind, if not the easiest. Leatherworking...... not so much.