Going to cover the basic arms warrior principles in this to start (gearing, gemming, enchants, spec, etc. etc.)

Spec:

There are two basic arms warrior specs

For Incite the basic spec is the 55/8/8 (http://www.wowhead.com/?talent#LhrhbfIt0obRdGuiohxZbI)
For Improved Execute the spec is 54/17/0 (http://www.wowhead.com/?talent#LhrhbfIt00bRdGuioGx00xb)

The Improved Execute spec will be the best spec for you if your gear level is T8 or below. Once your gear roughly passes that level the Incite spec will be superior. As always if your raid needs Commanding Presence or Improved Demoralizing Shout (i.e. if there isn’t a ret pally in the group) the execute spec is the one you would use.

The incite spec requires more crit and much better rage management but when done correctly will net a higher dps number. The incite spec thrives on fights with high incoming damage (Twins, BQL, festergut) but will still perform well with good rage management on other fights. Imp. Execute spec gets a moderate buff with t10 4p but will still underperform due to bad scaling with str.

And I have to go to class now so more later tonight.