More on Professions

Leatherworking is a great profession to make your own armor as you are leveling, and it does have some great consumables to sell in the form of armor patches and leg armors.  Craftable PVP gear and a few end game recipes round out most of what one commons sells with Leatherworking.  

Tailoring is decently approachable, with its own built in gathering skill since Wrath.  Basically when a tailor loots a mob that drops cloth, typically humanoids, they have an increased chance to receive more cloth.  Unlike most other professions, tailoring has products to sell at multiple points not just end game.  One big money maker for tailors is the bag market.  Tailors make not only standard bags but some of the specialty bags used by other professions.

Blacksmithing is a bit of a grind, but not any worse than any of the others.  Much like leatherworking it is mostly useful for the character as they are leveling to fill out spots in gear that haven't been filled by quest rewards.  At end game you can make a decent profit selling belt buckles, PVP gear, rods for enchanters to make enchanting rods,

The barrier to leveling alchemy is the need to gather copious amounts of herbs to create potions, elixirs and flasks while leveling up.  Inscription has driven up the price of herbs to the point that they are much more expensive on the auction house, but they are also much more plentiful as well.  Having power leveled three alchemists it isn't impossible to accomplish.  Alchemy still has specializations allowing you to focus on making flasks, elixirs or transmutes.  While flasks are always useful, and elixirs are handy in a dire situation, being able to transmute elements and create gems is road to wealth for many Alchemists.  

Mining and Herbalism are both referred to as gathering professions because they consist of gathering materials for other professions.  Gathering professions used to be the easiest to skill up as you leveled up your character.  With the changes made in Cataclysm to speed up leveling you will level out of an area before you have completely skilled up your gathering profession.  Gathering professions are powerful money makers at the beginning of an expansion as characters race to power level their main professions.  They also can be steady earners if you get into niche markets.  With Mining you can effectively flip ore on the Auction house by buying raw ore, and smelting it into bars if the bar price is sufficient for you to make a profit.