Due to his Skill set, Attack Speed is a Breakpoint the Barbarian cares about. Due to the complexity, Attack Speed would go beyond the scope of this post. Check out the d2planner to simulate your Breakpoints.

When using a Shield, the Barbarian has a % Chance to Block. When successfully blocking, he enters a block animation. Increasing your +% Faster Block Rate decreases the time your Barbarian needs to execute it.

Your Cast Rate increases the rate at which you can use spells. Increasing your +% Faster Cast Rate decreases the time required for a cast. The Action Flag determines at which Frame the used Skill is actually triggered.

When being hit, there is a chance that you get stunned. Increasing your +% Faster Hit Recovery decreases the time your Barbarian needs to recover from this stun.

Legend says that when the world was very young the tribes of the Northern Steppes were given a sacred charge. Somewhere deep within the great mountain, Arreat, lies a source of great power, crucial to the well being of all humanity. The tribes were tasked to act as guardians of this artifact. They have shaped their way of life in observance of this power and fulfilling their sacred duty.
Steeped in mystery and tradition, these people refer to themselves as the "Children of Bul-Kathos," the great and ancient king. To better protect their lands from outside forces, they adopted a nomadic lifestyle, frequently moving within the confines of the Steppes and maintaining few permanent settlements. Isolating themselves from the world outside their territories, they eschew the use of magics and complex machinery, as they believe these things can only weaken their resolve developed over so many years.
The Children of Bul-Kathos have developed a kinship with the land and have learned to harness the primal energies within nature to enhance their own substantial physical prowess. It is because of this, together with their freedom from the trappings of the outside world, that the Western Kingdoms have historically referred to these tribes as "Barbarians," an epithet that belies the rich cultural and spiritual history these people truly possess. Although some trade with these curious bands of nomads, they do so only along the outermost borders of their lands. All intrusions into the territory surrounding Mount Arreat are forbidden, and warriors from the northern tribes are quick to thwart any incursions. Every foreign attempt at conquest has been met with fierce and decisive resistance.
An account of one skirmish recounts how hordes of Barbarian tribesmen silently appeared where none had been but moments before. Their bodies painted in mysterious designs and their faces howling as they charged like the fierce mountain winds, the tribesmen descended on the invaders. Fully half of the trespassing army immediately dropped their weapons and fled, the remainder were set upon by the Northmen with fervor that none of the battle-hardened invaders had ever witnessed. No mercy was asked and none was given, but in the end, when the outlanders sounded a full retreat, no chase was given either… at least none that could be observed.
Since news of Diablo's re-emergence has spread, a small number of Barbarian warriors have begun roving the lands outside the Steppes, prepared for war and seeking information regarding the recent activities of the Prime Evils.