Combat Rogue is incredible. It does not level fast. You will have downtime and will be targeted in PvP engagements before you have full use of your toolkit. Dots and being kited will make leveling rough.
A bonus is you can sap and loot things, and you will have the option to pickpocket through the duration of your time playing a Rogue, making gold a complete and total non-issue. I think @ 60 RFD runs netted me 45g/hour. After ranking and the raid week is over, I ended up having many alts with several thousand gold each due to my Rogue. Made a Warrior and he had a Lionheart and Devilsaur set at 53 and 56, a pair of Stronghold Gauntlets, Might Bracers, and an epic mount, all at 60, before I even started farming for his bis and rank. Entirely from RFD and stockpiling material / cured rugged hides (leatherworking).
As combat you will want to go 20/31, traditionally as an Orc or Human if you want to focus on PvE. Humans get sword skill as a racial, and as white auto attacks are nearly 60% of your total damage done (with Slice and Dice 100% uptime), reducing the amount of reduction to attacks via glancing blow is almost paramount. Orcs have blood fury, which can be used in conjunction with juju flurry and adrenaline rush + blade flurry, for a staggering bonus to attack rating on a 53% speed increase (again, with slice and dice).
The big thing with combat leveling, is you can spec into Riposte. More often than not, you will be solo leveling. A Rogue is a lone wolf in that sense. It’s slower, yet quite easier. Having an attack that does as much % damage multiplier as backstab (150%) for a paltry energy cost, that ALSO disarms a target, is just incredible. You can have strings where you parry an enemy attack 2-3 times in a row, and just completely shred them, all while taking minimal damage due to the disarm.
Rogue raid spots are competitive. Rogues do 1 job in raid, and that is do damage. You don’t have to decurse, you can’t blind many mobs, and you offer no group buff. Your only job is to do damage. Being that they are one of the strongest 1v1 PvP classes in Vanilla, and are undoubtedly the strongest pure ganking class, many players prefer not to have to respec back and forth or be bothered with raid jobs like a Mage having to decurse, a Warlock on banish duty, a Hunter chain-pulling, etc. Simply put, no one expects much from a Rogue in raids. People gravitate to them for this reason. So, do your homework, and DPS hard.
I could give you as much information as you need, just respond with whatever you have questions on. I played a Rogue deep into BWL in Vanilla and have completed Naxxramas on 2 private servers as a Rogue.