Not really any preffered proffesion. Atm I have none and am level 61. I plan to level to 80, making what I can from buying low and selling normal, then employing tactics such as argent tournament pets to make money. Hopefully the money I make while leveling will also give me a good amount to manipulate the AH with.
Blackwolf, I already read those posts, they are quite useful ^^
Well, then you better get to 80 fast, because as time goes by, the price of those pets will lower. While at the moment you can sell one for 2,000 gold if you're lucky, in about a month, the price may have been halved.
And yes, the money you'll make until 80 (specially in Northrend) will be very good to start manipulating the AH. Considering you won't spend most of it on some nice purple or something similar, that is.