It has been said before but some viable choices for Druid:
Skin / Leatherworking [Tribal] - Tribal Leatherworking is best for druids since their gear can help both Resto/Feral druids.
Herb / Alchemy - This is my personal favorite since I get to make use of many potions as a druid[resto]. I'm level 60 druid and during ZG/MC runs, it is nice to have some Major Mana Potions that I can rely on, as well as Dreamless Sleep Potions and Mageblood potions. [Stat boosting potions for feral are also avaliable]
Skin / Herb - With Herbalism, you're able to sell what you don't need, and for when you come to end-game, you're capable of getting an alchemist in your guild or anywhere in the server to make them for you for a tip. Skinning is mostly a money-maker unless you're collecting the materials for a gear.
Mine / Engineer - I hear that many PVP druids tend to have Engineer since Engineering helps alot with it, I personally have no experiance with Engineering so I couldn't say.
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Overall, I would recommend at least Skinning/Herbalism until at least level 40 in order to make money for your mount, or even level 60 if you wish to for your epic mount. Later on, this will give you the option to choose either Leatherworking [Tribal] or pick Alchemy with it. However, you will not notice the full potential of alchemy until you also pick up fishing. Fishing, alone is a great profession which you should get and level to 300 for sure even if you don't have alchemy since making money with fishing is often also very easy.