best chance earn gold with a short time is AH, try think AH like a RL stock market, buy stuff that you know its very low price(mostly sold by gold seller, they undercut WAY too much), and re-sell it, wait tomorrow at mailbox and collect gold.

other way is buy TBC(58~62lvl) green or vanila green(55~60lvl) DE, enchant the enchantment that can only be use in heirloom item, put it in AH, those sell heaps of profit.

the other way being pug H daily with guild(fast run), /roll green stuff, DE, AH,
submit daily H=bout25g,

whats your other prof anyway?