To some this sounded a bit creepy, but others tried to be helpful. One suggestion was to level to 70 and follow the instructions in the guides. I have to disagree with that suggestion. Part of the point of leveling is to learn to play your class along the way. Many pointed out resources for up-and-coming rogues.
Bonar of Dragonblight took the time to offer a friendly, though not entirely eloquent, list of suggestions:
1) Combat is a nice leveling spec. Grab Riposte as well - it'll mitigate damage and is like a sinister strike for ten energy. Don't forget to grab BF, AR, combat potency, blah blah blah... as far as weapon specializations go... people will say "GO SWARDSWARDSWARDSWARDSWARDSWARD OMG NOOB," but really you have to consider the best equipment available to you before considering a specialization. That being said, it's probably prohibitively expensive for an alt to respec every three levels when he finds a new fist/sword/mace that is 3 DPS higher than his old one. Your best bet is SWARDSWARDSWARDSWARDSWARDSWARDSWARDSWARDSWARDSWARDOMGOMG.
2) Use your cooldowns - Blade Flurry, Adrenaline Rush, and Evasion are too good and on cooldowns too short to be used as "OHSHI--" buttons. Double pull when you've got BF, 3x/4x pull when you've got BF/AR/Evasion up. It helps mix things up as well.
3) Slice and Dice is your friend, and always will be. Your first combo point(s) on a mob should be spent on SnDing him ASAP.
4) Just because you HAVE stealth doesn't mean you need to spend all of your time in it. When I was leveling it surprised me how many Rogues thought it was cool to stay in stealth when moving from spawn to spawn. It's an incredibly sweet class feature that lets you skip a bunch of tedious crap, but Jesus, guys - lrn2aggroradius? Hell, sometimes it's just faster to run up to his face and sinister strike him for your first CP.
5) Put the weapon with the highest damage range in your MH. Weapon speed doesn't matter, even if this means putting your slower weapon in your OH. You'll run into this issue when you have both the RFD and SM swords. It feels so wrong, but you know it's right. Damage range, people - srs bizness.
The original poster does seem earnest in her willingness to learn a new and difficult class. My guess is that she will read up on the suggestions, but still find many of her questions unanswered. I hope she finds someone to show her around.
Would you be willing to take on a mentor/apprentice relationship in WoW?