Flasks and fish feasts can make a killing if you time it right. I put a bunch on they day that 3.3.5 was released and everybody went to try RS. Wednesdays seems like a good time to auction consumables.
Edit: Thouht I posted it already, but looks like I was wrong
Alchemy and mining isn't a good combo, since there isn't anything useful you get from mining directly to use in alchemy. For the purpose of making money, I would say that jewelcrafting would be a good choice, with blacksmithing at second. Alchemy is good with herbalism to get the mats, and some people put alchemy and jc together to transmute and then cut gems.
The easiest way to make money would be to get to 80 and then complete quests, both normal and dailies. At 80 they reward gold, and a level 80 quest gives around 13G.
Fish feasts are also a good money maker, since they are used for raids. All of the mats can be fished from WG without moving around, but you'll need high fishing (350+) and 450 cooking (i think) to get it.
You can also use two gathering professions. Since you have mining, the best option would be skinning, then you don't have to switch tracking the whole time. Unless you hate killings mobs to farm them (like I do). I would focus more on Northrend mats though, because more people will need it. Lower level ore/etc might fetch a higher price on the AH, but it's a smaller market for them.
