First, my resume: 54ish combat/sword-spec on a pvp server (Mal'Ganis) and an almost-36 dagger/imp sap on Terenas.
Second, what do you plan on doing w/ your rogue? just pve/pvp or some of both? If both, which will you focus on? These things affect your talent selections. There are a few core talents that are must-haves, IMO, regardless of what build you use:
Assassination: Imp Evis, Malice, Ruthlessness, Lethality
Combat: Imp SS
I really enjoy rogues. They are my "sit back, relax, and leave me alone" class. Therefore, I never worried about how long it took me to kill a mob. Plus hit, attack pwr, and agil are the stats to look for. Slower weap w/ highest max dmg in m/h, fastest weap o/h (this holds true regardless of weap type used).
My combat/sword rogue was going 18/33/0 (I haven't played him since the patch). I went w/ swords because I didn't think I could mash buttons fast enough to play a dagger build well. With swords, you're relying on solid white damage to burn down you target at a steady pace. Additional talents for this build include: Deflection, Precision, Riposte, Duel Wield Spec, Blade Flury, Sword Spec, Imp SnD. I'm leaving out the new talents because I'm not very familiar with them. Typical attack sequence was CS > SnD > SS > SS > SS (if needed) > Evis.
When I came to Terenas, I started a dagger rogue, just to see if I could mash the buttons fast enough to become really good at this play style. I found that it wasn't bad at all in pve, but I'm not very good at pvp (I should say I'm bad at pvp, period, regardless of class played). I struggled w/ talents for this one, because daggers can go deep into any of the 3 trees (unlike sword/mace, which can really only go combat). I decided to try Imp Sap, although I'm still working on getting it. I've read it becomes useless in 20+ raids. Since dagger rogues can go deep into any of the three trees, it is hard to narrow down must-have talents. Generally speaking, Assassination tree for bigger burst dmg, Combat for steady consistent dmg, and Subtelty for pvp (at least to Preparation). Additional talents to consider: Leathality, Cold Blood, Seal Fate, Imp Gouge, Imp BS, Opportunity, Imp Ambush. My typical sequence is CS > BS > Gouge > BS > Evis. Usually, the 5-point Evis is overkill, but I humor myself trying to set new Evis records this way.
If you decide to go dagger (which I'd recommend), do not let your sword skill lag too far behind. Arguably, many people find dual-wielding swords better for raiding; you may be one.
Poisons, poisons, poisons. If you do not always have poisons on your weapons, delete your toon and roll a pally. Use Crippling Poison on m/h for mobs that run, Instant poison on m/h for mobs that don't. Use Instant poison on o/h. Sub Deadly Poison (or whichever one DOTs and stacks 5 times) for Instant poison on longer/elite fights. Use sharpening stones for mobs immune to poison.
When soloing, always pickpocket; it's quick, free cash. If grouped, ask if its OK to PP, they may not care (at least in-guild). You can PP as long as you are not in combat (the mob can be). When grouped w/ Shuranda's hunter, I stealth up, her bear begins tanking, I PP, then a speedy death: Amb/CS > BS > Evis;
Keep you Lockpicking skill @ max. It can earn you tips opening lockboxes, and some chests in instances are locked.
Thistle Tea is a must for pvp; it can be useful (sometimes) for pve. It only requires cooking skill of 60ish and gives instant max energy. Take herbalism to pick it yourself (comes from mageroyal, briarthorn, and something else).
Alchemy is highly recommended/must-have for pvp. I do fine pve w/o it, but I'm only lvl 35 at the moment.
I have leatherworking and have made a lot of my armor. I don't normally buy things off the AH, so my craftable items are generally better than what drops off of mobs or obtained as quest rewards. Take herbalism and mining/skinning, sell mats on AH and buy armor/weap upgrades on AH. Keep some swiftthistle onhand for you tea and sell the rest for big bucks.
When a boss/elite fight is going to take a while, do not overlook Rupture (DOT). The damage done is "pure," bypassing armor reduction, whereas Evis damage is reduced by armor.
My fingers are starting to hurt, so I'm done for now.