If we look at low level Rogue abilities such as: Sinister Strike, Backstab, Ambush, etc. We see a consistent trend of a percentage of Weapon Damage. Damage for these abilities is calculated:
base weapon damage + constant * (attack power)/14
In the case of daggers this constant is 1.7 and other one handed weapons 2.4. This is known as AP normalization. Additionally, only the main hand weapon is used in these calculations. As a result it is ideal to use a slower main hand weapon until you have sufficient attack power to influence your choice.
In the case of Rogues it is common to use Daggers as certain abilities (such as Backstab) require them. At latter levels you will gain other abilities which influence this selection (Combat Swords, Mutilate, Hemorrhage, etc), but at lower levels, slow Main Hand daggers is a preferred choice. A longer discussion of Main Hand weapon choices can be found here.
As a subtlety Rogue your "bread and butter" ability is Hemorrhage which does 110% MH damage (159.5% if its a Dagger as Daggers tend to be faster). I would suggest Initiative + Improve Ambush, making your combat look as follows:
- Ambush (or cheap shot)
- Gouge (later you'll use Kidney shot later in the order).
- Backstab (or Hemorrhage)
- Finishing Move
- Hemo -> Repeat till Gouge/Cheapshot come back up or you have the Combo Points to Finishing move
Garrote can be a good opener if the target stays alive for the full duration. As most mobs won't while leveling, Ambush is usually the better choice.
As a Subtly Rogue you also trade on Dodge, Ap, Crit and Armor pen (the last of which you won't get in bulk till much later). Keep in mind that Agility gives you 3/4, but is not as cost effective as straight AP due to Deadliness.
Source
You need 8 guild members in the raid for all pre-cataclysm raid achievements in 10, 20, and 25 man zones. 40 man raids require 10 guild members. 5 man dungeon achievements require 4.
And, with the exception of Naxx 40, yes, all of the old 40 man zones (MC, BWL, and AQ40) are still in the game.
Best Answer
As was discussed in this question:
Hit is the premier secondary stat for rogues, especially so for assassination rogues, as a larger portion of their damage comes from their poisons, which use spell hit.
You don't need to reach the so called "hit-cap", but until you reach the spell hit cap, theorycrafting indicates your next best secondary stats are mastery, and then haste.
Expertise is of minimal overall importance, beating out only crit in terms of estimated overall worth. (See here)
In short -- do not reforge anything into expertise -- you're better off reforging into hit or mastery (do note that the amount of hit rating you need to reach the caps are lower than what the Elitest Jerks link shows, as they are primarily considering raiding, which involve higher level'd bosses.)