Windranger is a ranged intelligence hero most commonly played as a solo offlaner, but she is a highly versatile hero capable of fitting into most line-ups and can be played as a mid semi-carry or as a lane supporter.
She has good lockdown with Shackleshot, good burst nuke damage with Powershot, and an escape that makes her a viable offlaner in Windrun.
Skills
Get one point in Windrun and then Shackleshot to ensure your safety in the offlane.
Max Powershot first, then Shackleshot, then finally Windrun.
Don't skill your ultimate, Focus Fire, at level 6. It is typically taken at level 10 or 13 and used mainly for tower/base pushing.
Items
Starting Items: A set of Tangos, a Healing Salve and three Branches. Plus either a Ring of Protection or Observer Wards.
Early Items: Boots of Speed, Magic Wand, Ring of Basilius.
Typical Core: Phase Boots, Force Staff, Magic Wand, Ring of Basilius.
Supporter Core: Arcane Boots, Mekanism or Pipe of Insight, Magic Wand, Ring of Basilius.
Luxury Options: Aghanim's Scepter, Maelstrom, Orchid, Drums of Endurance, Scythe of Vyse, Black King Bar, Daedalus, Monkey King Bar.
Situational: Medallion, Blink Dagger, Necronomicon, Linken's Sphere.