List of Heroes with Auras or Buffs

Auras that increase right-click damage or attack speed:

• Elder Titan: Natural Order (base armor reduction to enemies)
• Luna: Lunar Blessing (fixed damage boost)
• Vengeful Spirit: Vengeance Aura (% base dmg boost)
• Shadow Fiend (armor reduction aura)
• Beastmaster:  Inner Beast (
• Drow: Precision Aura (Ranged only)

Auras with another benefit:

• Obsidian Destroyer/Devourer:  Essence Aura
• Necrophos / Necrolyte:  Heartstopper Aura
• Rubick:  Null Field (magic resist increase)
• Crystal Maiden: Arcane Aura (global mana regen)
• Doom:  Scorched Earth (damage)
• Wraith King:  Vampiric Aura (lifesteal)

Temporary Allied Group Buffs:

• Lycan:  Howl (flat attack damage buff)
• Ancient Apparition: Chilling Touch (magic damage to right clicks)
• Undying: Flesh Golem (+0-30% damage amp)

Items with Auras:

• Headdress (hp regen)
• Mekanism (hp regen)
• Pipe of Insight (hp regen)
• Radiance (damage aura)
• Shiva's Guard (attack speed slow)

Balanced Team Examples based around Stacking Auras:

#1: 

Chaos Knight safelane carry + Venge support/roaming + WK/CM support/roaming
Sfiend mid
Beastmaster/Elder Titan solo offlane

#2:

Drow Mid
Elder Titan solo offlane
Luna + Venge + Rubick Safe

#3:
Shadowfiend mid
Beastmaster solo offlane
Drow + Visage + Venge safelane
PS - you'll never draft this combo - one of the heroes will get banned.  It's also heavily countered by Omniknight's ultimate.

Ranged attack buffing

Carries that Give buff:  Drow, Troll (temporary), Shadow Fiend, Luna, Lycan (temporary)

Supports that Give Buff:  Ogre (Lust), Venge (Wave, Aura), Beastmaster (Inner Beast), Elder Titan (Aura), AA (chilling touch)

Buff beneficiaries:  Sniper, DragonKnight, Wind Ranger (all benefit heavily from auras)

Team Example - Ranged Attack Buffing:

BeastMaster / Elder Titan solo offlane

SF mid

DragonKnight solo safelane

Ogre + Venge Roaming