I would recommend utilizing your mining to get gold thru saronite/titanium. I would go on a 3way split with saronite ore, 1 part to vendor (smelted to bars of course), 1 part to AH (be watchful on days and prices that arebest on your realm), and 1 part store for other professions (JC, Eng, BS, Alch). Go 2 part on the Titanium, 1 part AH (I wouldn't smelt it, its more valuable in long run as raw ore cause of JC's) and 1 part professions (JC, Eng, BS).
If you do not have a secondary profession for your rogue, I would suggest herbalism. Alot of profiles for northrend can do both herb and mine at the same time. And the herbs you get can fall under the same rules as the titanium above, 1 part AH, and 1 part for professions.
Once you have your farmer going smoothly, make sure NOT to do this majority of the time. I would work on rotating between farming for mats and leveling toons. I've found leveling 2 or 3 toons in a rotation and adding farming into that works great. Farm for mats til you get a set desired amount (i usually go for about 2 or 3 hours at a time), then i do my seperation. After that i rotate my leveling toons. sometimes I will level til the double XP is expired on each, and other times i will go for a period of time. On non-80's, the weekends that have BG"s i'm able to run that are Call to Arms, i run those religiously due to the insane amounts of Exp. Example being, in a 15 hr period one toon leveled 15 levels (mid range).
If your in it for personal gain and not really for 'profit', at least for now, then after awhile you'll notice your gold going up slowly and steadly. As you reach certain points, go back and start leveling your professions on your other toons. With JC, Eng, and BS, its good to find a few profiles that you can run that gather mats for leveling these. I would recommend WoW Professions (wow-professions.com) Its not 100% accurate but pretty close. It will give you an idea of the number and type of mats needed for each profession. You could (i've proven this) spend about 5 days of heavy mining (takes majority of your time) with a 450 Miner and gather enough mats and gold to powerlevel all 3 of those professions. But it takes practice and planning. Just don't be greedy, you'll find it goes a long way.
After you get your toons leveled, and more professions maxed your gold in-flow will raise higher and higher
On one account i will sit at an average of 10k to 15k at any time between my toons and this is the account i actually play for personal, not profit. Also considering all my toons (7 80's) all have epic flight and a couple have hogs and mamoth mounts.
Just take your time, plan things out and don't be afraid to hit a few dry spots here and there, you'll find your niche. And if you REALLY want to hit the ground running find out what server pan is on and take over his server, i hear he loves a good challenge at that
