Here is my take on a Boros Humans deck.
Deck breakdown:
Creatures-
4x Champion of the Parish - amazing humans card, and a 1 cost makes it perfect aggro
3x Fiend Hunter - adds early game control as well as a good blocker
2x Knight of Glory - low cost protection from black
3x Knight of the White Orchid - really nice low cost extra mana
2x Mentor of the Meek - awesome card draw for cheap
1x Odric, Master Tactician - perfect for mid game and controlling opponents blockers.
2x Precinct Captain - perfect pair for Champion of the Parish
2x Silverblade Paladin - gives another creature double strike perfect for early-mid game
4x Skyknight Legionnaire - great Boros card, and has haste!
4x Student of Warfare - amazing early mana sink,
1x Truefire Paladin - low cost, and you can give him first strike/ +2/0
2x Wojek Halberdiers - Super low cost, with battalion
Instants-
1x Boros Charm - the most brutal of all the charms
3x Brave the Elements - amazing for keeping creatures like champion of the parish alive
4x Lightning Bolt - cheap spot control
2x Lightning Helix - more spot control with life gain
2x Warleader's Helix expensive, but good burn/life gain.
Enchantments-
1x Chained to the Rocks - cheap control
Lands -
3x Kabira Crossroads - +2 life, can't beat that
2x Boros Guildgate - dual land, meh
7x Mountain - back to the basics
6x Plains - yeah, more basic lands
