Basically, the things you need to do are stack to-hit, damage, and things that boost charges.
Roughly at L10 you should have the following
- Rageblood class feature (might as well get access to Swift Charge)
- L1 At-Will Howling Strike (can be used on a charge, extra damage at-will)
- L1 Feat Two handed weapon expertise (feat tax, extra damage on charge)
- L2 Feat weapon proficiency Gouge (barbs should have nice toys)
- L4 Feat MC Fighter/Rogue (opens surprising charge shenanigans)
- L6 Feat Surprising Charge (1[W] on charge with CA? I'll take that)
- L8 Feat Weapon Focus Spear/Axe (extra damage on spear attacks)
- L10 Feat Powerful Charge/Deadly Rage (you decide, both probably merit inclusion on an exclusively damage oriented build, either way, MOAR damage)
As far as equipment goes, there are two essential pieces for the heroic barbarian.
- Horned Helm (extra d6 on a charge)
- Vanguard or Jagged Weapon (extra d8 on a charge for Vanguard, Jagged weapon for expanded crit range)
- Badge of the Berserker (doesn't promote damage, but goes a long way to making sure you can keep charging and stay alive)
- Boots of Adept Charging (again, doesn't boost your damage, but they keep you alive)
- Iron Armbands of Power (+2 melee damage)
Basically, your strategy with feats, powers and equipment are to stack damage.
Charge is your best move for many reasons, but the big reasons are the +1 to hit, and the fact that it's an easy way to stack gobs of damage.
With this character, at L10, with Powerful Charge and the Vanguard weapon, you're doing the following on a charge with CA (assuming Str 22):
To Hit: 2 + 6 + 5 + 2 + 1 + 1 + 2 = +19
Damage: 4d5+4 + 2d6 + d8 + 6 + 2 + 1 + 1 + 2 + 2 = 39.5 on average
On top of that you don't take OA's when charging, and you can shift a square afterwards. And while you're raging, your speed is 8.
Jagged vs Vanguard came up in the comments below and I should share the results of the math. For a +20 to hit on a charge, and +19 to hit on a MBA (both +3 weapons), the math is as follows:
Vanguard Howling: 4d5+4 + 2d6 + d8 + 6 + 2 + 1 + 1 + 2 + 3 = 40.5, 59
Jagged Howling: 4d5+4 + 2d6 + 6 + 2 + 1 + 1 + 2 + 3 = 36, 51
MBA: 2d5+4 + 3 + 2 + 1 = 15, 20
3d8 = 13.5
ongoing 10 = 15
.75 * 40.5 + .05 * (59 + 10.5 + .65 * 15 + .05 * (20 + 13.5) =
30.375 + .05 * (69.5 + 9.75 + 1.525) = 34.72
.70 * 36 + .1 * (51 + 15 + .6 * 15 + .1 * (20 + 15)) =
25.2 + .1 * ( 66 + 9 + 3.5) = 33.05
This gives the edge to the Vanguard weapon on the charge. However, in general, the Jagged weapon is the stronger weapon for the Barbarian as he wants the expanded critical to trigger Rampage. The Paragon tier feat Charging Rampage seals the deal on this as it allows rampage to become a charge attack which bumps the damage substantially.