Professions can definitely be a great gold-maker in MoP Classic, especially things like Alchemy, Inscription, and Jewelcrafting since they feed into raiding demand. The trick is to know which mats spike in price and when to craft vs. sell raw materials.
Mists of Pandaria Classic Guides have some pretty solid walkthroughs for efficient leveling paths and money-making tips. I found those Mists of Pandaria Classic Guides useful because they also explain which markets are worth investing in without wasting gold on unnecessary recipes.