I Myself have been playing a rogue alt lately. And i found advice in other class forums hardly compare to the mage forums. Kudos to all of you who make mages so great.
Back on the rogue. I'm no expert. I know combat is the top raid spec, im leveling my rogue as combat. A few things i've come to learn.
-Dont spec into a weapon specialization, you'll be changing them as you level.
-Keep them stunned, the longer there stunned the less damage you take, less downtime eating after fights.
-Blade furry is amazing when a pull goes bad.
-Like most classes your pretty weak when you start out, once you get cheap shot, kidney shot and such, killing becomes very easy, but thats not till around lvl 30.
-Keep your weapons updated, weather its buying off AH or running instances, having up to level weapons is a must. Your dependant on your weapon damage.
I'm sure theres boat loads of more advice and better, but this is what i've gathered a bit off of my lvl 37 rogue.