The first part of the darkmoon series deals with Darkmoon Card Death
and the second with Insane in the Membrane Achieve
Now that the darkmoon faire has ended, you might think that your hopes in working with the Darkmoon Faction is over. But fear not, thanks to inscription, there are still other ways to curry favor or trade for gold with the darkmoon people.
With the advent of 3.0 and inscription, low level scribes have been able to create new low level version of darkmoon decks that instead of giving card trinkets, give out BoE equipment for different slots at different level brackets.
The most important thing to take note about these darkmoon deck series is that they are
1) Bind on Equip
2) Can be turned in at any time and anywhere
You can buy one of these decks today, fly to a desolate location like desolace or tanaris, and still summon a darkmoon quest-giver and turn in those low level decks. Each deck also gives comparative reputation, generally 25 rep(the major decks are worth 350 rep), as well as experience points, which you can also use to level up your alts. (they work out to be about 1 normal quest at their respective levels)
The decks are:
Rogues Deck lvl 10
Swords Deck lvl 20
Mages Deck lvl 30
Demons Deck lvl 40
All of these decks drops items that are very good (in general) for both leveling classes and twinks, especially since they can be equipped the instant you turn into that level bracket and are comparable to blues within their range. Except for rogues and swords which give you items with random attributes, you can choose the exact reward for your decks, depending on which is more profitable on your server.
If you're starting off, I recommend you buy swords deck to try your hand at this market. I generally can purchase Swords deck for 5-10 gold, and sell the resulting item for a few times that price like 40-65 gold sometimes. Occasionally however I get a badly itemized shoulder slot and I would simply give it away or vendor it. Since the initial startup cost is quite low, and you can be almost any level to use this, its a pretty good way to go about making gold if you're new to wow too.
If you yourself are a scribe, then you might have some of this hanging around. Using ink of the sea conversions and using up your idle rare pigments, you can make the mages and demons deck for a rather low price and sell your extras. You can then sell the quest turn in item on the AH for usually twice to thrice your cost price.