I just recently hit level 40, and I found myself with very little gold. I made the mistake of buying gear and using all my skinning leather to up my leatherworking to 200 instead of selling it all, and not taking two gathering professions until later in my character's levels. This is probably because I have little to no WoW experience at all before nostalrius, and just found out about saving money as you level towards 40 :O
Since I just hit 40 and find myself with ~5g, I'd like to know what would be the best way to get to 100g at least and be able to get a mount. Should I be farming mobs on level to sell gray/whites/drops? Or should I be duoing lower level dungeons with my leveling buddy to get better drops to sell? I'm new to the whole WoW experience as a whole, so some money making tips at level 40 would be a great help :3